Re: [time-nuts] OT: Prologix GPIB and HP3478A...It's Alive!!!
Hi Abdul and Group, I'm beginning to feel like I am a manic depressive.. I keep going from the lowest lows to the highest highs... Well things are pretty high right now. Here's how I got there: First, I took my Prologix adapter apart to have a look see under the microscope. ... Abdul probably won't speak to me ever again after I describe what I did... But I'm an engineer. I can't help myself. It's in my genes. In looking the board over over, I discovered that one of the data pins on the GPIB connector was bent out of line where it passed into the board. A classic sign of solder blocked hole that prevented the pin from passing through the board and getting soldered. This is it, I thought. The pin even wiggled funny. So I needed to take the thumb screws out and get to the bottom side of the board and repair the joint. Well, Abdul obviously didn't want me to do that, as he epoxied a nut onto each screw to keep it retained... a little over kill there Abdul. I like that! If you ever run into something like this, your soldering iron can be your friend... that and a little patience. I heated the nut until it was smoking hot, and screwed the thumb screw right out... Sounds much easier than it really was... That's where the patience part comes in. After I got the board out, I discovered something odd, the pin that was bent up stuck through the board enough so that Abdul had clipped off the excess after soldering the board. Hmmm? Well, I sucked out the joint, straightened the pin, resoldered it, and tested the silly thing anyway... Hope springs eternal, as they say. It worked! My 7854 was up and running, and being controlled, and all of that really neat stuff, and t h e n, i t w a si g n o r i n g e v e r y t h i n gt h a t I s e n t t o i t... Damn! We are hitting one of those lows again. So, I plugged my trusty HP85B into the scope, and tried to control the scope, and ... it didn't work either! It's getting a little hard for me to escape the conclusion that there is something wrong with my scope, and it's an intermittent too... I love problems that are intermittent. They allow me to waste inordinate amounts of time, speak new swear words I don't usually use.. All that kind of stuff that makes it feel good to be a man. The first place I decided to look was the 7854's GPIB connector, since the problem seemed to have something to do with exercising the connector. When I got the connector where I could see it, I noticed that Tektronix committed a major fooboo with this connector. They needed it to stick out from the board a little bit further than the solder tails would allow, so they checked to see that nobody was looking, and just soldered the pads with the solder tails somewhat below the surface... Not a great recipe for success... Or as someone once said it was one of those things that puts the suck in success. I sucked out all of the joints, and made triple damn sure that the new joints were getting properly wetted with solder, and made a little fillet on the other side of the board, and tried things out...and... It works!!! Remember what I said about manic-depressive? Well this is one of those high times. It seems to be ok. Now we just have to let it run for a while. With any luck at all, it will work long enough that I will completely forget I ever went through this series of events. Hopefully I can keep this mess running until I get my Tektronix 547 transformer core experiments finished, my report written, some pretty pictures made, and a couple of transformers rewound We'll see. Thanks Abdul for providing me with such good entertainment! -Chuck Harris Prologix wrote: Hi Chuck, Please make sure the adapter is properly seated. Also, see if using a GPIB cable makes a difference. If you are still having trouble I am happy to send you a replacement unit. Regards, Abdul -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Chuck Harris This is beginning to look more and more like I have a bad Prologix adapter. Oh Abdul?? -Chuck Harris ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OT: Prologix GPIB and HP3478A...
++eot_char is usually okay. The particular problem I was hacking at the time was a screen dump from a Tek scope (TDS 754A). The screen dump is an 8-bit binary file in a weird image format and you don't know exactly how many bytes are going to be dumped (~50k bytes), but it does set EOI with the last byte sent. ++eot_char doesn't work 100% since the chosen EOT character might be binary data or it might be the EOT character. The reason I asked is that the solution would be cleaner if you could do a ++read eoi and then issue some other ++ query command to ask if EOI was set on the previous read. jeff Prologix wrote: Hello Jeff, Thanks for the compliments. Much appreciated. You may configure the Prologix adapter (using ++eot_enable and ++eot_char) to send (append, really) a user-specified character to USB ouput when it detects EOI. By checking for the character you can determine if EOI was asserted. Regards, Abdul -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jeff Mock I have a slightly off-topic question about reads. When issuing a ++read eoi, is it possible to tell whether an EOI was actually returned by the instrument or whether the read was terminated by timeout or block size limitation? jeff ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OT: Prologix GPIB and HP3478A...
John Miles wrote: Did you try sending ++auto 0 before powering up the 3478A? Yes. It does not prevent the lockup (lockout?) As I said in an earlier post, the 3478A is not giving any indication that it is addressed, or connected to the bus at all. It *always* does when the HP85B is connected as the controller. This setting is persistent, so you should only have to do it once to keep the board from automatically addressing the 3478A to talk. Also try disconnecting any/all other RS-232 devices from your PC during initial testing, and/or try a different USB port. The port is the only one the laptop has, and it works just fine. The laptop is running kermit under linux, so it is a very basic connection. The problem is clearly entirely within my Prologix. I cannot yet say whether it is a bug in the firmware, a circuit failure, or a design flaw. The 3478A, and the cables used work just fine with an HP85B. -Chuck Harris ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OT: Prologix GPIB and HP3478A...
Hi Didier, Sending ++addr 23 (the address of my 3478A), locks up my prologix until it is disconnected from the 3478A. Here is how I tell: ++ver [Prologix GPIB - USB Converter Version 5.0] ++addr 23 ++ver [the silence is deafening!] ++read 10 [the slience is deafening!] ... pull the prologix off of the bus... ++ver [Prologix GPIB - USB Converter Version 5.0] ... we're back! ... -Chuck Harris Didier Juges wrote: Chuck, Sending ++addr 09; ++read 10; with my Prologix to the HP 3478A returns a single reading just fine. Didier KO4BB ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OT: Prologix GPIB and HP3478A...
Hi Jeff, Most (all?) GPIB instruments use 7-bit data. You should be OK choosing eot_char in the 0x80-0xFF range. I agree though, your's is a cleaner solution. Regards, Abdul -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jeff Mock Sent: Wednesday, November 28, 2007 1:04 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] OT: Prologix GPIB and HP3478A... ++eot_char is usually okay. The particular problem I was hacking at the time was a screen dump from a Tek scope (TDS 754A). The screen dump is an 8-bit binary file in a weird image format and you don't know exactly how many bytes are going to be dumped (~50k bytes), but it does set EOI with the last byte sent. ++eot_char doesn't work 100% since the chosen EOT character might be binary data or it might be the EOT character. The reason I asked is that the solution would be cleaner if you could do a ++read eoi and then issue some other ++ query command to ask if EOI was set on the previous read. jeff Prologix wrote: Hello Jeff, Thanks for the compliments. Much appreciated. You may configure the Prologix adapter (using ++eot_enable and ++eot_char) to send (append, really) a user-specified character to USB ouput when it detects EOI. By checking for the character you can determine if EOI was asserted. Regards, Abdul -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jeff Mock I have a slightly off-topic question about reads. When issuing a ++read eoi, is it possible to tell whether an EOI was actually returned by the instrument or whether the read was terminated by timeout or block size limitation? jeff ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OT: Prologix GPIB and HP3478A...The Answer!
And the answer is: My Prologix USB - GPIB Version 5.0 adapter has insufficient pullups to drive my HP3478A DVM. Once I put another (older) turned on device on the bus, the Prologix snapped to attention and works as it should. Abdul, there is a very good reason why the 488 bus driver chips exist. The 488 standard *requires* that no listener load the bus with more than 1 TTL input load, and *requires* that every active Talker or Controller have a pull up/ pull down resistor on every data and control pin that is equal to this: ~ +5V ~ | ~ 3.1K ~ | ~ Out-+ ~ | ~ 6.2K ~ | ~ GND It would appear that my 3478A is in a non loading tristate mode until it is addressed, and you are relying on the devices on the bus to do their own pull up. Clearly that isn't always going to work. -Chuck Harris Chuck Harris wrote: Prologix wrote: Hello Chuck, It appears that 3478A sends data continuously as soon as it is addressed to talk. Since the Prologix adapter is busy processing GPIB data it is unable to respond to USB commands. I don't think the 3478A is sending anything at all. If it was, it should be showing some of the annunciators on its LCD display, like TLK, LSTN, RMT, SRQ, or something. But it isn't. I think the Prologix isn't capable of driving the 3478A, logic level wise, and is waiting in vain for the 3478A to respond to a signal the 3478A cannot see. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OT: Prologix GPIB and HP3478A...The Answer!
Hi Chuck, Good work identifying the problem! Leaving out the bus driver chips was a conscious decision based on available board space and was not made lightly. Extensive testing had shown that not to be an issue, so far. In fact, yours is the first reported case of a drive related problem. However, we consider even one incident to be one too many, and will be revisiting the decision during a future release. Thank you for brining this to our attention. Regards, Abdul -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Chuck Harris Sent: Wednesday, November 28, 2007 7:47 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] OT: Prologix GPIB and HP3478A...The Answer! And the answer is: My Prologix USB - GPIB Version 5.0 adapter has insufficient pullups to drive my HP3478A DVM. Once I put another (older) turned on device on the bus, the Prologix snapped to attention and works as it should. Abdul, there is a very good reason why the 488 bus driver chips exist. The 488 standard *requires* that no listener load the bus with more than 1 TTL input load, and *requires* that every active Talker or Controller have a pull up/ pull down resistor on every data and control pin that is equal to this: ~ +5V ~ | ~ 3.1K ~ | ~ Out-+ ~ | ~ 6.2K ~ | ~ GND It would appear that my 3478A is in a non loading tristate mode until it is addressed, and you are relying on the devices on the bus to do their own pull up. Clearly that isn't always going to work. -Chuck Harris Chuck Harris wrote: Prologix wrote: Hello Chuck, It appears that 3478A sends data continuously as soon as it is addressed to talk. Since the Prologix adapter is busy processing GPIB data it is unable to respond to USB commands. I don't think the 3478A is sending anything at all. If it was, it should be showing some of the annunciators on its LCD display, like TLK, LSTN, RMT, SRQ, or something. But it isn't. I think the Prologix isn't capable of driving the 3478A, logic level wise, and is waiting in vain for the 3478A to respond to a signal the 3478A cannot see. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OT: Prologix GPIB and HP3478A...The Answer!
Hi Abdul, Bear in mind that it isn't proved that my HP3478A is working flawlessly. It is possible that it has a flaw in its 488 drivers that prevents them from ever putting pull ups on the bus. This wouldn't be noticed with a controller that fully met the 488 standard, such as the one in the HP85B, or on a 488 bus that had more than one instrument. You may still be safe with your cost saving decision. Didier Juges says his 3478A works just fine with his Prologix controller. So we need to ask him if he has ever successfully used his Prologix controller with only the HP3478A on the bus... and what is the build number of his 3478A. Mine is: 2911A523XX. -Chuck Harris Prologix wrote: Hi Chuck, Good work identifying the problem! Leaving out the bus driver chips was a conscious decision based on available board space and was not made lightly. Extensive testing had shown that not to be an issue, so far. In fact, yours is the first reported case of a drive related problem. However, we consider even one incident to be one too many, and will be revisiting the decision during a future release. Thank you for brining this to our attention. Regards, Abdul ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OT: Prologix GPIB and HP3478A...The Answer!
Interesting point there. I seem to recall quite a few pullup/pulldown options in the Atmel port-configuration registers; this may just be a matter of selecting a mode that looks more like the resistor configuration Chuck mentioned. Personally, I think it's fine if you support only 99% of the GPIB devices out there and leave the remaining 1% to the competition. Your boards have proven compatible with an incredibly-wide array of instruments at this point. If the 3478A problem can't be fixed in software, I think the best answer is, Sorry, we don't support that one, here's a refund. It certainly isn't worth adding more chips (and cost) to the board IMHO. -- john, KE5FX -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Prologix Sent: Wednesday, November 28, 2007 10:25 AM To: 'Discussion of precise time and frequency measurement' Subject: Re: [time-nuts] OT: Prologix GPIB and HP3478A...The Answer! Hi Chuck, Good work identifying the problem! Leaving out the bus driver chips was a conscious decision based on available board space and was not made lightly. Extensive testing had shown that not to be an issue, so far. In fact, yours is the first reported case of a drive related problem. However, we consider even one incident to be one too many, and will be revisiting the decision during a future release. Thank you for brining this to our attention. Regards, Abdul ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OT: Prologix GPIB and HP3478A...The Answer!
Hi John, I agree in part. If it is known that certain GPIB instruments are not supportable, then it is essential to have that documented fact easily available to the buyer. Thus far, the Prologix website, and documentation, make no mention of any possible limitations, or deficiencies. [For instance, it clearly cannot support the maximum defined GPIB system, or cable lengths. That should have been mentioned.] The GPIB standard is very well defined. There really is no reason to expect that a commercially made controller wouldn't be able to operate with any GPIB controlled instrument. The HP87B's controller will operate any device, and I am sure that the controllers I designed as a graduate student would as well. I would be angry, except that I already knew that the design had a major short cut in it before I bought my Prologix. If you recall, I addressed that issue many months back on this forum. I bought my Prologix controller based on the good reports that all of you guys posted. And the need to control a single device, a Tektronix 7854. It will do that, so I am satisfied. The Go away kid, you bother me! approach won't win over many customers. -Chuck Harris John Miles wrote: Interesting point there. I seem to recall quite a few pullup/pulldown options in the Atmel port-configuration registers; this may just be a matter of selecting a mode that looks more like the resistor configuration Chuck mentioned. Personally, I think it's fine if you support only 99% of the GPIB devices out there and leave the remaining 1% to the competition. Your boards have proven compatible with an incredibly-wide array of instruments at this point. If the 3478A problem can't be fixed in software, I think the best answer is, Sorry, we don't support that one, here's a refund. It certainly isn't worth adding more chips (and cost) to the board IMHO. -- john, KE5FX ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OT: Prologix GPIB and HP3478A...The Answer!
In message [EMAIL PROTECTED], John Miles writes: If the 3478A problem can't be fixed in software, I think the best answer is, Sorry, we don't support that one, here's a refund. It certainly isn't worth adding more chips (and cost) to the board IMHO. I fully agree. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [EMAIL PROTECTED] | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OT: Prologix GPIB and HP3478A...The Answer!
In message [EMAIL PROTECTED], Prologix writes: Hi Chuck, Good work identifying the problem! Leaving out the bus driver chips was a conscious decision based on available board space and was not made lightly. Extensive testing had shown that not to be an issue, so far. In fact, yours is the first reported case of a drive related problem. However, we consider even one incident to be one too many, and will be revisiting the decision during a future release. I think I can report having seen the problem as well, only not realizing the cause, because it worked flawlessly when I put my HP59401A Bus Analyser on the bus. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [EMAIL PROTECTED] | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OT: Prologix GPIB and HP3478A...The Answer!
Hi John, I have run mine with at least a half-dozen daisy-chained instruments on 20-30 feet of cabling with no problem at all. Some of the 8650-series signal generators cause loading problems when they're powered off, but that's true with the NI boards as well. With the loading limits on most small microprocessors, this seems reasonable. And I am glad to hear that it is possible. It extends the use of the Prologix from one adapter/one box model, to being able to run something like an 8505A network analyzer where there are 3 or 4 boxes all on the bus. I waited for version 5.00, with its multi address capability, because I had envisioned using it one day to add automation to my 8505A system. I would be angry, except that I already knew that the design had a major short cut in it before I bought my Prologix. If you recall, I addressed that issue many months back on this forum. If you want 'anger', try spending time supporting other boards, especially the off-brands that claim to be NI488.2-compatible. Anger is only the second or third stage of the grief that process brings. Abdul has been great with his support. I have no complaints. I would have some, if I didn't jump into this deal already knowing pretty well the potential caveats of the design. A given instrument's support of the IEEE-488 standard is a little different from a competitor's support of NI's house brand standard. Kind of like trying to be a windows compatible operating system when microsoft only wants you to buy its operating system. And GPIB itself is not exactly a textbook example of how to design a multiuser bus. Certainly not. But how many use it that way? It is generally used as a single controller with multiple talker/listeners, working sequentially when addressed by the controller. I bought my Prologix controller based on the good reports that all of you guys posted. And the need to control a single device, a Tektronix 7854. It will do that, so I am satisfied. The Go away kid, you bother me! approach won't win over many customers. I'm sorry; who said that? It was the tone of your suggestion that everyone that buys a unit and finds out that it doesn't work on such-and-such an instrument should be given his money back, and sent away. I am all in favor of a product that has known design constraints that keep its price low. I bought this adapter knowing that was true. It would be nice, though, to have the option of having the same design available with true 488 drivers. I think that capability would smoke out a few more customers at very little extra cost. I need to clarify that I've helped Abdul with some testing now and again, but have absolutely no other business relationship with him, other than the fact that I happen to live in the same area, and regularly let him (and pretty much anyone else who asks) drop by to use my test gear. That is what I believed to be true. You have said nothing to imply any other relationship. -Chuck Harris ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OT: Prologix GPIB and HP3478A...The Answer!
In message [EMAIL PROTECTED], Chuck Harris writes: Hi John, I have run mine with at least a half-dozen daisy-chained instruments on 20-30 feet of cabling with no problem at all. Some of the 8650-series signal generators cause loading problems when they're powered off, but that's true with the NI boards as well. Part of the IEEE spec is certain limitations on how many devices on the bus can be powered off. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [EMAIL PROTECTED] | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OT: Prologix GPIB and HP3478A...The Answer!
In message [EMAIL PROTECTED], John Miles writes: Agreed, documenting this sort of limitation is pretty important, now that it's known. That said, his intent has always been one dongle per instrument, plugged directly into the back without any cables at all. The first few generations of the board used a DIP switch to set a hardwired address, in fact. I bought two Prologix (since the shipping is such a large fraction here to .eu I might as well) I have found that it works best if I use one Prologix for my Tek 'scope and the other one for all the HP-kit (7 instruments, most of which are powered down at any one time) -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [EMAIL PROTECTED] | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OT: Prologix GPIB and HP3478A...The Answer!
From: Poul-Henning Kamp [EMAIL PROTECTED] Subject: Re: [time-nuts] OT: Prologix GPIB and HP3478A...The Answer! Date: Wed, 28 Nov 2007 21:58:59 + Message-ID: [EMAIL PROTECTED] In message [EMAIL PROTECTED], John Miles writes: Agreed, documenting this sort of limitation is pretty important, now that it's known. That said, his intent has always been one dongle per instrument, plugged directly into the back without any cables at all. The first few generations of the board used a DIP switch to set a hardwired address, in fact. I bought two Prologix (since the shipping is such a large fraction here to .eu I might as well) I have found that it works best if I use one Prologix for my Tek 'scope and the other one for all the HP-kit (7 instruments, most of which are powered down at any one time) It is so nice that Tek and HP could agree on a standard for printouts. :P That was irony for you. From whatever I have seen, they have never worked together. The Tek Spec we have at work has a nice feature. TWO GPIB connectors. One for remote instrument control and the other for printouts only. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OT: Prologix GPIB and HP3478A...The Answer!
Yet it works fine with mine, even with or without a number of other instruments on the bus, powered or not. I have not come across that problem with either the Prologix of the IOTech Micro488/P which also uses a microcontroller (Motorola 68HC705C4) to directly drive the bus (no GPIB driver chip). There has to be something else wrong, maybe the 3478 is partially defective and requires too much drive, or is lacking the right pullup. The fact that it works with the HP 85 indicates that it is not completely dead, but there could be something wrong with it that makes it incompatible with the Prologix. I agree that it is always best to follow the standard, but in this case, I doubt it is the root cause of the problem. My HP 3478A has serial number 2619A36441, switch 6 (Power ON SRQ) is down (0), switch 7 (not sure what it does) is up (1) and switch 8 (50/60 Hz) is down (0) Didier -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Chuck Harris Sent: Wednesday, November 28, 2007 9:47 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] OT: Prologix GPIB and HP3478A...The Answer! And the answer is: My Prologix USB - GPIB Version 5.0 adapter has insufficient pullups to drive my HP3478A DVM. Once I put another (older) turned on device on the bus, the Prologix snapped to attention and works as it should. Abdul, there is a very good reason why the 488 bus driver chips exist. The 488 standard *requires* that no listener load the bus with more than 1 TTL input load, and *requires* that every active Talker or Controller have a pull up/ pull down resistor on every data and control pin that is equal to this: ~ +5V ~ | ~ 3.1K ~ | ~ Out-+ ~ | ~ 6.2K ~ | ~ GND It would appear that my 3478A is in a non loading tristate mode until it is addressed, and you are relying on the devices on the bus to do their own pull up. Clearly that isn't always going to work. -Chuck Harris Chuck Harris wrote: Prologix wrote: Hello Chuck, It appears that 3478A sends data continuously as soon as it is addressed to talk. Since the Prologix adapter is busy processing GPIB data it is unable to respond to USB commands. I don't think the 3478A is sending anything at all. If it was, it should be showing some of the annunciators on its LCD display, like TLK, LSTN, RMT, SRQ, or something. But it isn't. I think the Prologix isn't capable of driving the 3478A, logic level wise, and is waiting in vain for the 3478A to respond to a signal the 3478A cannot see. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OT: Prologix GPIB and HP3478A...The Answer!
Chuck, Most replies to your questions came before I read this :-) The last tests I reported on yesterday were done with only the 3478 on the bus. I'll be glad to check the waveform with a scope if that can help. Didier KO4BB -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Chuck Harris Sent: Wednesday, November 28, 2007 12:45 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] OT: Prologix GPIB and HP3478A...The Answer! Hi Abdul, Bear in mind that it isn't proved that my HP3478A is working flawlessly. It is possible that it has a flaw in its 488 drivers that prevents them from ever putting pull ups on the bus. This wouldn't be noticed with a controller that fully met the 488 standard, such as the one in the HP85B, or on a 488 bus that had more than one instrument. You may still be safe with your cost saving decision. Didier Juges says his 3478A works just fine with his Prologix controller. So we need to ask him if he has ever successfully used his Prologix controller with only the HP3478A on the bus... and what is the build number of his 3478A. Mine is: 2911A523XX. -Chuck Harris ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OT: Prologix GPIB and HP3478A...The Answer!
The IOTech Micro488/P has the same basic design (microcontroller drives bus directly) and therefore should be assumed to have the same potential deficiency and costs about $500 today new from the factory (serial interface only). The only limitation they show on their web site is that it can only control up to 8 instruments, there is no mention of data rate or cable length. I have two of them and so far they control everything I have thrown at them. Being powered from the serial bus (they draw about 5mA), they don't have much pull-up capability by themselves, probably very far from the IEEE-488 spec requirements. They advertise it as being intended for laptops, but many laptop serial ports won't provide the drive power/voltage it requires... http://www.iotech.com/catalog/ieee/mini_controller.html I would like to make sure we find out where the problem is. I agree with John that the Prologix has proven to be dependable and that the design approach was a reasonable compromise. Measurement Computing sells a GPIB driver chip that is in a small surface mount package, but it costs more than the Atmel chip Abdul is using, and it's just a driver. Didier -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Chuck Harris Sent: Wednesday, November 28, 2007 1:12 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] OT: Prologix GPIB and HP3478A...The Answer! Hi John, I agree in part. If it is known that certain GPIB instruments are not supportable, then it is essential to have that documented fact easily available to the buyer. Thus far, the Prologix website, and documentation, make no mention of any possible limitations, or deficiencies. [For instance, it clearly cannot support the maximum defined GPIB system, or cable lengths. That should have been mentioned.] The GPIB standard is very well defined. There really is no reason to expect that a commercially made controller wouldn't be able to operate with any GPIB controlled instrument. The HP87B's controller will operate any device, and I am sure that the controllers I designed as a graduate student would as well. I would be angry, except that I already knew that the design had a major short cut in it before I bought my Prologix. If you recall, I addressed that issue many months back on this forum. I bought my Prologix controller based on the good reports that all of you guys posted. And the need to control a single device, a Tektronix 7854. It will do that, so I am satisfied. The Go away kid, you bother me! approach won't win over many customers. -Chuck Harris John Miles wrote: Interesting point there. I seem to recall quite a few pullup/pulldown options in the Atmel port-configuration registers; this may just be a matter of selecting a mode that looks more like the resistor configuration Chuck mentioned. Personally, I think it's fine if you support only 99% of the GPIB devices out there and leave the remaining 1% to the competition. Your boards have proven compatible with an incredibly-wide array of instruments at this point. If the 3478A problem can't be fixed in software, I think the best answer is, Sorry, we don't support that one, here's a refund. It certainly isn't worth adding more chips (and cost) to the board IMHO. -- john, KE5FX ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OT: Prologix GPIB and HP3478A...The Answer!
I need to clarify that I've helped Abdul with some testing now and again, but have absolutely no other business relationship with him, other than the fact that I happen to live in the same area, and regularly let him (and pretty much anyone else who asks) drop by to use my test gear. That is what I believed to be true. You have said nothing to imply any other relationship. No problem; I just didn't want people (including lurkers) assuming that Abdul shares my opinion or is unduly influenced by it. The real issue with trying to be all things to everyone isn't just adding a driver chip to the board. It's that you have to write firmware and software to round out the compatibility picture. Abdul has thought about adding an NI488.2 driver layer, which I agree would be nice, but then he'd be in the business of supporting every NI488.2 application ever written, including some flaky ones that only work because of undocumented behavior in NI's API. /Not that I would ever write any code like that,,, //ducks, whistles, shifts eyes, walks away slowly -- john, KE5FX ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OT: Prologix GPIB and HP3478A...The Answer!
Didier Juges wrote: Yet it works fine with mine, even with or without a number of other instruments on the bus, powered or not. I have not come across that problem with either the Prologix of the IOTech Micro488/P which also uses a microcontroller (Motorola 68HC705C4) to directly drive the bus (no GPIB driver chip). Ok, that pretty well rounds out the picture. The 3478A uses the 75ALS160 and 161 bus drivers. Both are designed to be either tristate or pullup drivers depending on the signal on a single pin. I will have to put a scope on mine and see what it is being told to do. Driver chips do fail... all too often, actually. There has to be something else wrong, maybe the 3478 is partially defective and requires too much drive, or is lacking the right pullup. The fact that it works with the HP 85 indicates that it is not completely dead, but there could be something wrong with it that makes it incompatible with the Prologix. I agree that it is always best to follow the standard, but in this case, I doubt it is the root cause of the problem. My HP 3478A has serial number 2619A36441, switch 6 (Power ON SRQ) is down (0), switch 7 (not sure what it does) is up (1) and switch 8 (50/60 Hz) is down (0) Switch 2 (what you call 7) is said by HP to be not used. I have tried mine in both positions, and see no change. -Chuck Harris ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OT: Prologix GPIB and HP3478A...The Answer!
Didier Juges wrote: I would like to make sure we find out where the problem is. I agree with John that the Prologix has proven to be dependable and that the design approach was a reasonable compromise. Measurement Computing sells a GPIB driver chip that is in a small surface mount package, but it costs more than the Atmel chip Abdul is using, and it's just a driver. Didier Making changes for the sake of making changes is probably a folly. The Prologix concept is sound the way it is, but it should have some mention of the known limitations. It would be nice if we could find a couple of other folks that have 3478's to test with the Prologix unit. Because the 3478 uses 75ALS160/161's, it could have the tristate/pullup modes selected by the microprocessor. So it could be a part failure, or a firmware problem. I will try and determine which is true, but it will have to wait for a while. Thanks to all for their help and input into my problem -Chuck Harris ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OT: Prologix GPIB and HP3478A...The Answer!
Well, I have a 3478A, but unfortunately not a Prologix. If I get my hands on one I could add a data point. Personally, I think there is a fault in that particular 3478's driver chips. Daun -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Chuck Harris Sent: Wednesday, November 28, 2007 8:06 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] OT: Prologix GPIB and HP3478A...The Answer! Didier Juges wrote: I would like to make sure we find out where the problem is. I agree with John that the Prologix has proven to be dependable and that the design approach was a reasonable compromise. Measurement Computing sells a GPIB driver chip that is in a small surface mount package, but it costs more than the Atmel chip Abdul is using, and it's just a driver. Didier Making changes for the sake of making changes is probably a folly. The Prologix concept is sound the way it is, but it should have some mention of the known limitations. It would be nice if we could find a couple of other folks that have 3478's to test with the Prologix unit. Because the 3478 uses 75ALS160/161's, it could have the tristate/pullup modes selected by the microprocessor. So it could be a part failure, or a firmware problem. I will try and determine which is true, but it will have to wait for a while. Thanks to all for their help and input into my problem -Chuck Harris ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OT: Prologix GPIB and HP3478A...The Answer!
Daun -- Guess who you see frequently who has a Prologix you might able to borrow... John Daun Yeagley said the following on 11/28/2007 08:45 PM: Well, I have a 3478A, but unfortunately not a Prologix. If I get my hands on one I could add a data point. Personally, I think there is a fault in that particular 3478's driver chips. Daun -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Chuck Harris Sent: Wednesday, November 28, 2007 8:06 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] OT: Prologix GPIB and HP3478A...The Answer! Didier Juges wrote: I would like to make sure we find out where the problem is. I agree with John that the Prologix has proven to be dependable and that the design approach was a reasonable compromise. Measurement Computing sells a GPIB driver chip that is in a small surface mount package, but it costs more than the Atmel chip Abdul is using, and it's just a driver. Didier Making changes for the sake of making changes is probably a folly. The Prologix concept is sound the way it is, but it should have some mention of the known limitations. It would be nice if we could find a couple of other folks that have 3478's to test with the Prologix unit. Because the 3478 uses 75ALS160/161's, it could have the tristate/pullup modes selected by the microprocessor. So it could be a part failure, or a firmware problem. I will try and determine which is true, but it will have to wait for a while. Thanks to all for their help and input into my problem -Chuck Harris ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OT: Prologix GPIB and HP3478A...The Answer!
I am aware of at least 2 more 3478 at my workplace, one of them actually has been in my office for so long I forgot about it. It has worked fine with the older Prologix controller (the one without a case,) with nothing else on the bus now that I think of it :-) Different firmware but same Atmel chip I believe. I used the 3478/Prologix as a temperature data logger with a thermistor for a while. I liked the 3478 so much I bought one for myself on eBay, that's how I ended up with one :-) On this subject, I recently wrote a short Visual basic program to help me with temperature calculations from thermistors. It is at http://www.ko4bb.com/Thermistor Get your free copy while they last :-) Didier KO4BB -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Daun Yeagley Sent: Wednesday, November 28, 2007 7:45 PM To: 'Discussion of precise time and frequency measurement' Subject: Re: [time-nuts] OT: Prologix GPIB and HP3478A...The Answer! Well, I have a 3478A, but unfortunately not a Prologix. If I get my hands on one I could add a data point. Personally, I think there is a fault in that particular 3478's driver chips. Daun ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OT: Prologix GPIB and HP3478A...The Plot thickens!!
Hi Duan, I was thinking that way until I moved on to try another instrument, my Tektronix 7854, only to find that the Prologix can't address it either! The Prologix doesn't hang like it did on the 3478A, but the Tektronix acts as if it isn't on the bus at all. I know we have some communication going on because if I force SRQ on the tektronix, and issue a ++srq command to the Prologix, the Prologix returns 1 showing the SRQ line is asserted. But if I do a ++spoll 10 the 7854's address) the SRQ line is not reset. As an experiment, I put my 3437A on the bus to act as surrogate pull up resistors; the 3437A works, but the 7854 is still deaf to the Prologix's charms. It comes as no surprise to me, however, that when I drive the 7854 with my HP85B, the 7854 works just fine. [Everything works with the HP85B.,, Over the nearly 20 years that I have used an HP85B, I have never found an instrument that it couldn't make play straight out of the box.] This is beginning to look more and more like I have a bad Prologix adapter. Oh Abdul?? -Chuck Harris Daun Yeagley wrote: Well, I have a 3478A, but unfortunately not a Prologix. If I get my hands on one I could add a data point. Personally, I think there is a fault in that particular 3478's driver chips. Daun ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OT: Prologix GPIB and HP3478A...The Answer!
Hi Didier, I am more and more coming to the conclusion that my 3478A is just fine, but my Prologix adapter is a victim of infant mortality. It can't address my Tektronix 7854 either. -Chuck Harris Didier Juges wrote: I am aware of at least 2 more 3478 at my workplace, one of them actually has been in my office for so long I forgot about it. It has worked fine with the older Prologix controller (the one without a case,) with nothing else on the ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OT: Prologix GPIB and HP3478A...The Plot thickens!!
Hi Chuck That's certainly a possibility that your Prologix has a problem. The comments on the HP-85, etc. parallel mine. I worked for HP starting back in 1979, as an HPIB Specialist. My first experience was with the 9825 (HPL), and when the HP-85 came out, it became the workhorse, although the 9835 and 9845 were fancier and certainly faster. My favorite though was the 200 and 300 series with the *real* RMB (Rocky Mountain Basic, nicknamed so because it was developed in the Fort Collins Desktop Computer Division (DCD). I still have one or two, and has always been my favorite for doing instrument I/O. Now I do a lot of it using the Microsoft stuff... VB, and more recently C#. Life for I/O was certainly a lot simpler and foolproof in the RMB days. Now, it makes me attempt to go bald! Daun -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Chuck Harris Sent: Wednesday, November 28, 2007 10:41 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] OT: Prologix GPIB and HP3478A...The Plot thickens!! Hi Duan, I was thinking that way until I moved on to try another instrument, my Tektronix 7854, only to find that the Prologix can't address it either! The Prologix doesn't hang like it did on the 3478A, but the Tektronix acts as if it isn't on the bus at all. I know we have some communication going on because if I force SRQ on the tektronix, and issue a ++srq command to the Prologix, the Prologix returns 1 showing the SRQ line is asserted. But if I do a ++spoll 10 the 7854's address) the SRQ line is not reset. As an experiment, I put my 3437A on the bus to act as surrogate pull up resistors; the 3437A works, but the 7854 is still deaf to the Prologix's charms. It comes as no surprise to me, however, that when I drive the 7854 with my HP85B, the 7854 works just fine. [Everything works with the HP85B.,, Over the nearly 20 years that I have used an HP85B, I have never found an instrument that it couldn't make play straight out of the box.] This is beginning to look more and more like I have a bad Prologix adapter. Oh Abdul?? -Chuck Harris Daun Yeagley wrote: Well, I have a 3478A, but unfortunately not a Prologix. If I get my hands on one I could add a data point. Personally, I think there is a fault in that particular 3478's driver chips. Daun ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OT: Prologix GPIB and HP3478A...
Chuck, I have used my HP 3478A with my Prologix controller (and several other GPIB controllers), but I have not upgraded the firmware to 5.0 (I think I am still at 4.61 or something like that). I will try and let you know. The 3478 is a relatively recent instrument (as far as GPIB features/capability/compliance is concerned), so I am surprised you would have problems. Didier KO4BB -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Chuck Harris Sent: Tuesday, November 27, 2007 9:34 PM To: Discussion of precise time and frequency measurement Subject: [time-nuts] OT: Prologix GPIB and HP3478A... Hi Gang! I just bought a Prologix GPIB - USB converter model, version 5.00, and I am having some problems. It works fine on some of my instruments, but it just locks up when I hook it to an HP3478A DVM. The DVM is known good, and works great with my HP85B (doesn't everything?). Basically, if I do any commands that require bus activity, the Prologix locks up and refuses to respond to even the ++ver command. When I unplug the HP3478A, the Prologix once again finds its happy spot, and responds normally. Any ideas? -Chuck Harris ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.5.503 / Virus Database: 269.16.8/1154 - Release Date: 11/27/2007 11:40 AM ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OT: Prologix GPIB and HP3478A...
Hi Chuck: It may be timing. The 85 and the 3478 are old and slow. Have you tried adding wait statements after you send any command to give the 3478 time to think about it? Also it may be good to send CRLFEOI after each command then do the wait. Have Fun, Brooke Clarke http://www.PRC68.com http://www.precisionclock.com http://www.prc68.com/I/WebCam2.shtml 24/7 Sky-Weather-Astronomy Cam Chuck Harris wrote: Hi Gang! I just bought a Prologix GPIB - USB converter model, version 5.00, and I am having some problems. It works fine on some of my instruments, but it just locks up when I hook it to an HP3478A DVM. The DVM is known good, and works great with my HP85B (doesn't everything?). Basically, if I do any commands that require bus activity, the Prologix locks up and refuses to respond to even the ++ver command. When I unplug the HP3478A, the Prologix once again finds its happy spot, and responds normally. Any ideas? -Chuck Harris ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OT: Prologix GPIB and HP3478A...
Hello Chuck, It appears that 3478A sends data continuously as soon as it is addressed to talk. Since the Prologix adapter is busy processing GPIB data it is unable to respond to USB commands. One solution is to turn read-after-write off (++auto 0) before connecting the adapter to 3478A, and then use ++read command to read one measurement at a time. Please see the manual (www.prologix.biz) for ++read command options. The other option is to set 3478A to one-reading-per-trigger mode using T3 device command. See HP3478 manual (pages 39, 59). Then use the ++trg command to trigger the device. ++auto must be set to 1 in this case. Regards, Abdul -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Chuck Harris Sent: Tuesday, November 27, 2007 7:34 PM To: Discussion of precise time and frequency measurement Subject: [time-nuts] OT: Prologix GPIB and HP3478A... Hi Gang! I just bought a Prologix GPIB - USB converter model, version 5.00, and I am having some problems. It works fine on some of my instruments, but it just locks up when I hook it to an HP3478A DVM. The DVM is known good, and works great with my HP85B (doesn't everything?). Basically, if I do any commands that require bus activity, the Prologix locks up and refuses to respond to even the ++ver command. When I unplug the HP3478A, the Prologix once again finds its happy spot, and responds normally. Any ideas? -Chuck Harris ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OT: Prologix GPIB and HP3478A...
On Tue, 27 Nov 2007, Prologix wrote: Hello Chuck, It appears that 3478A sends data continuously as soon as it is addressed to talk. Since the Prologix adapter is busy processing GPIB data it is unable to respond to USB commands. One solution is to turn read-after-write off (++auto 0) before connecting the adapter to 3478A, and then use ++read command to read one measurement at a time. Please see the manual (www.prologix.biz) for ++read command options. The other option is to set 3478A to one-reading-per-trigger mode using T3 device command. See HP3478 manual (pages 39, 59). Then use the ++trg command to trigger the device. ++auto must be set to 1 in this case. Regards, Abdul Excellent answer! I do not have either piece of equipment but I can certainly say that even though I am now using NI GPIB cards which are likely faster, I always program the instrument being queried to only send one response per trigger. I learned BASIC and also HPIB programming on a HP85 when it was the latest and greatest in 1980-81. Then later in another company I used the 9845 and then after that used the 9836. I think I must have learned from their wonderful documentation sets that this was the right way to take readings. It may well have been to avoid the timing issues you presented. Regards, Jeffrey Pawlan ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OT: Prologix GPIB and HP3478A...
Chuck, Sending ++addr 09; ++read 10; with my Prologix to the HP 3478A returns a single reading just fine. Didier KO4BB -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Chuck Harris Sent: Tuesday, November 27, 2007 9:34 PM To: Discussion of precise time and frequency measurement Subject: [time-nuts] OT: Prologix GPIB and HP3478A... Hi Gang! I just bought a Prologix GPIB - USB converter model, version 5.00, and I am having some problems. It works fine on some of my instruments, but it just locks up when I hook it to an HP3478A DVM. The DVM is known good, and works great with my HP85B (doesn't everything?). Basically, if I do any commands that require bus activity, the Prologix locks up and refuses to respond to even the ++ver command. When I unplug the HP3478A, the Prologix once again finds its happy spot, and responds normally. Any ideas? -Chuck Harris ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OT: Prologix GPIB and HP3478A...
Some instruments are pretty hard headed and can't be easily convinced to stop after just one piece of information. So Abdul implemented the ++read command. I know some people like that :-) Too bad ++read does not work with those... Didier KO4BB -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jeffrey Pawlan Sent: Tuesday, November 27, 2007 10:33 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] OT: Prologix GPIB and HP3478A... I always program the instrument being queried to only send one response per trigger. ... Jeffrey Pawlan ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OT: Prologix GPIB and HP3478A...
Prologix wrote: One solution is to turn read-after-write off (++auto 0) before connecting the adapter to 3478A, and then use ++read command to read one measurement at a time. Please see the manual (www.prologix.biz) for ++read command options. I nearly always turn off auto mode on the prologix. I've run into a number of slightly flaky problems when the prologix guesses to turn on the instrument to talk. I've never noticed a performance penalty because I need to issue a ++read command to the prologix whenever I want to read something back. I think the prologix device is great. I'm a linux guy, I haven't used windows in many years. NI has never really understood open source software. It was always a pain to have a reliable driver for the NI GPIB PCI cards, so I was quite happy to find something like the Prologix device that is reliable and has drivers that are totally open source and distributed as part of the linux kernel. I have a slightly off-topic question about reads. When issuing a ++read eoi, is it possible to tell whether an EOI was actually returned by the instrument or whether the read was terminated by timeout or block size limitation? jeff ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OT: Prologix GPIB and HP3478A...
Hi Brooke, I'm sending the commands as I type them in Kermit. Surely that is slow enough. I cannot send any commands to the 3478A. The simple act of asking the prologix to do anything other than ++ver, locks up the prologix so it ignores all USB traffic. The Prologix works fine with a 3438A, which is about as old as GPIB gets. Also with a 3437A, which is pretty old too. Something is broken here. The prologix is probably violating some timing requirement in the handshaking, and the 3478A isn't playing along. -Chuck Harris Brooke Clarke wrote: Hi Chuck: It may be timing. The 85 and the 3478 are old and slow. Have you tried adding wait statements after you send any command to give the 3478 time to think about it? Also it may be good to send CRLFEOI after each command then do the wait. Have Fun, Brooke Clarke ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OT: Prologix GPIB and HP3478A...
Chuck, The commands I copied in my previous post were sent very fast. My program sends the strings automatically when I click on a button, so fast timing is perfectly acceptable by the Prologix/3478A combination. Let me know if you need me to give you any particular configuration information of my setup. I use a program I wrote in Visual basic under XP, but I cannot see why it would not work from the keyboard, even though I have not tried... I have tried from the keyboard with the HP 3456A voltmeter at one time when Abdul asked me for testing purposes (the Prologix did not completely lock out, but was clearly overwhelmed by the amount of data returned by the meter), and after Abdul added the ++read eoi command, it worked fine too. I know you use Linux, so this program won't do you any good, and I do not have a Linux box handy in the shack at the moment, but if you wanted to try it, let me know. Didier KO4BB -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Chuck Harris Sent: Tuesday, November 27, 2007 11:55 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] OT: Prologix GPIB and HP3478A... Hi Brooke, I'm sending the commands as I type them in Kermit. Surely that is slow enough. I cannot send any commands to the 3478A. The simple act of asking the prologix to do anything other than ++ver, locks up the prologix so it ignores all USB traffic. The Prologix works fine with a 3438A, which is about as old as GPIB gets. Also with a 3437A, which is pretty old too. Something is broken here. The prologix is probably violating some timing requirement in the handshaking, and the 3478A isn't playing along. -Chuck Harris Brooke Clarke wrote: Hi Chuck: It may be timing. The 85 and the 3478 are old and slow. Have you tried adding wait statements after you send any command to give the 3478 time to think about it? Also it may be good to send CRLFEOI after each command then do the wait. Have Fun, Brooke Clarke ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OT: Prologix GPIB and HP3478A...
Did you try sending ++auto 0 before powering up the 3478A? This setting is persistent, so you should only have to do it once to keep the board from automatically addressing the 3478A to talk. Also try disconnecting any/all other RS-232 devices from your PC during initial testing, and/or try a different USB port. -- john, KE5FX -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Chuck Harris Sent: Tuesday, November 27, 2007 9:55 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] OT: Prologix GPIB and HP3478A... Hi Brooke, I'm sending the commands as I type them in Kermit. Surely that is slow enough. I cannot send any commands to the 3478A. The simple act of asking the prologix to do anything other than ++ver, locks up the prologix so it ignores all USB traffic. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OT: Prologix GPIB and HP3478A...
Hello Jeff, Thanks for the compliments. Much appreciated. You may configure the Prologix adapter (using ++eot_enable and ++eot_char) to send (append, really) a user-specified character to USB ouput when it detects EOI. By checking for the character you can determine if EOI was asserted. Regards, Abdul -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jeff Mock I have a slightly off-topic question about reads. When issuing a ++read eoi, is it possible to tell whether an EOI was actually returned by the instrument or whether the read was terminated by timeout or block size limitation? jeff ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OT: Prologix GPIB and HP3478A...
Prologix wrote: Hello Chuck, It appears that 3478A sends data continuously as soon as it is addressed to talk. Since the Prologix adapter is busy processing GPIB data it is unable to respond to USB commands. I don't think the 3478A is sending anything at all. If it was, it should be showing some of the annunciators on its LCD display, like TLK, LSTN, RMT, SRQ, or something. But it isn't. I think the Prologix isn't capable of driving the 3478A, logic level wise, and is waiting in vain for the 3478A to respond to a signal the 3478A cannot see. There truly is a reason why 488 bus driver chips exist. Something about the talker/controller's 220 ohm/330 ohm pull up/pull down terminator spec, and the 38ma pull down spec. One solution is to turn read-after-write off (++auto 0) before connecting the adapter to 3478A, and then use ++read command to read one measurement at a time. Please see the manual (www.prologix.biz) for ++read command options. Nope, doesn't work, locks it up on the first ++read command. The other option is to set 3478A to one-reading-per-trigger mode using T3 device command. See HP3478 manual (pages 39, 59). Then use the ++trg command to trigger the device. ++auto must be set to 1 in this case. Sending T3 locks up the Prologix. -Chuck Harris Regards, Abdul -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Chuck Harris Sent: Tuesday, November 27, 2007 7:34 PM To: Discussion of precise time and frequency measurement Subject: [time-nuts] OT: Prologix GPIB and HP3478A... Hi Gang! I just bought a Prologix GPIB - USB converter model, version 5.00, and I am having some problems. It works fine on some of my instruments, but it just locks up when I hook it to an HP3478A DVM. The DVM is known good, and works great with my HP85B (doesn't everything?). Basically, if I do any commands that require bus activity, the Prologix locks up and refuses to respond to even the ++ver command. When I unplug the HP3478A, the Prologix once again finds its happy spot, and responds normally. Any ideas? -Chuck Harris ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
