Re: [time-nuts] HP5335A GPIB questions.
Luke, the HP5335A was introduced in around 1980 and has an early (pre-IEEE-488.2) HP implementation of IEEE-488 which requires a terminator character at the end of each string. According to the manual, this terminator can be a comma, semicolon, space, carriage return, or line feed character. The delays are extremely important. The 5335A can and will hang if you don't wait long enough. In keeping with that, *do not* set your adapter to do an automatic read after sending data over the GPIB. Bill, Orin, Thank you! You solved my problem! It's working normally now! I was not sending a terminator at the end of the command and I had automatic read after send turned on. Setting to manual read, sending CR and then reading manually stopped the strange behavior. With a few lines of BASIC I'm now saving frequency readings to a file. I've already found that my home-built adapter won't work with Timelab. It has served it's purpose. With less than $10 worth of parts I was able to verify that the GPIB on my HP5335A is working. Now it's time to get a better GPIB adapter. I like the Prologix because It's easy for me to write code to access a com port. Do you know if the 82357 type adapters can be accessed as a com port? Any suggestions on what adapter to use? ___ 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] HP5335A GPIB questions.
Luke, the HP5335A was introduced in around 1980 and has an early (pre-IEEE-488.2) HP implementation of IEEE-488 which requires a terminator character at the end of each string. According to the manual, this terminator can be a comma, semicolon, space, carriage return, or line feed character. Later products (after about 1987) usually required a terminator of CR (carriage return), LF (line feed), or the hardware EOI (end or identify) termination method. In addition to the terminator character, your GPIB interface needs to change the bus transfer direction by unaddresing the HP5335A as a listener and making it a talker. Early IEEE-488 implementations in the late 1970's (IEEE-488 was introduced in 1975) and early 1980's often required explicit computer commands to assert and release the talk and listen commands, but by about 1990 the software commands usually performed these low level details for you automatically. So I suggest looking at the documentation for your GPIB interface and making sure you use a terminator character (from the list above) instead of only the EOI method of terminating commands, since I think the HP5335A will ignore the EOI line. Most GPIB interfaces in the past 20 years can be set to send a LF (ASCII 10 hex) character along with the EOI line transition to indicate the end of a command, and that should work. These old GPIB devices use very simple short cryptic commands, but they don't follow the later IEEE-488.2 and SCPI conventions. I'm sure you will be able to get this to work with the right configuration of termination character and talk/listen turnaround. -- Bill Byrom N5BB On Sat, Mar 21, 2015, at 09:24 PM, Luke Mester wrote: I recently bought a HP5335A counter and have some questions about operating the instrument with GPIB. I expect that a lot of time nuts are using this instrument and may be able to help. Please excuse me if this is a stupid question. This is my first GPIB instrument. After each GPIB command that I send I've found that I then need to send an RE (reset) command. If I Don't send RE the instrument takes no readings and has a blank display. For example I send FN9 to select period and get no readings until RE is sent. Is this normal? I'm currently talking to it with a USB to GPIB adapter and a terminal program. Since I had no idea if the GPIB interface was functional I didn't want to buy an expensive GPIB adapter. I build the cheapest GPIB adapter that I could find on the internet. It's possible that this is causing problems. It emulates a Prologix adapter. Here is a link if you're interested. HTTP://http://www.dalton.ax/gpib/ I've found that this adapter does not properly report the serial control line status. Because of this, Timelab won't detect the GPIB adapter. You can get Timelab to work if you choose the Acquire from counter in talk only mode option. -- Luke Mester http://mesterhome.com/ _ 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] HP5335A GPIB questions.
The 5335A is fussy. FWIW I used the following init string: IN,FN1,WA1\n Important: I then wait for 125 ms; that being the total time for IN,FN1,WA1 to execute per the 5335A manual. Only then, do I try to read data from the instrument. Pay careful attention to the times that commands take and don't try to access the 5335A before that time... expect it to sulk otherwise. After reading the first result, then I loop reading results. I have an additional delay of 100ms before reading each result. The comment in my code is: 5335A seems to sulk if we read too soon. I was using a real Prologix Ethernet GPIB adapter when I wrote this code. The delays are extremely important. The 5335A can and will hang if you don't wait long enough. In keeping with that, *do not* set your adapter to do an automatic read after sending data over the GPIB. Another thing to note is that the 5335A likes some kind of termination on its commands. I used CR using the ++eos=1 command to the Prologix. The unescaped '\n' in my init string ends the string to be sent over GPIB and '\r' is appended by the Prologix adapter. There is no need to send EOI after a command and the 5335A does not send EOI after the last character it sends.You have to read up to '\n' instead. You also want to make sure you don't timeout any read from the adapter before the gate time that is set on the 5335A. I used a 3s timeout with a gate of about 2s. I think that covers the gotchas that I know of! Orin. On Sat, Mar 21, 2015 at 7:24 PM, Luke Mester lmeste...@gmail.com wrote: I recently bought a HP5335A counter and have some questions about operating the instrument with GPIB. I expect that a lot of time nuts are using this instrument and may be able to help. Please excuse me if this is a stupid question. This is my first GPIB instrument. After each GPIB command that I send I've found that I then need to send an RE (reset) command. If I Don't send RE the instrument takes no readings and has a blank display. For example I send FN9 to select period and get no readings until RE is sent. Is this normal? I'm currently talking to it with a USB to GPIB adapter and a terminal program. Since I had no idea if the GPIB interface was functional I didn't want to buy an expensive GPIB adapter. I build the cheapest GPIB adapter that I could find on the internet. It's possible that this is causing problems. It emulates a Prologix adapter. Here is a link if you're interested. HTTP://http://www.dalton.ax/gpib/ I've found that this adapter does not properly report the serial control line status. Because of this, Timelab won't detect the GPIB adapter. You can get Timelab to work if you choose the Acquire from counter in talk only mode option. -- Luke Mester http://mesterhome.com/ ___ 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] HP5335A GPIB questions.
I recently bought a HP5335A counter and have some questions about operating the instrument with GPIB. I expect that a lot of time nuts are using this instrument and may be able to help. Please excuse me if this is a stupid question. This is my first GPIB instrument. After each GPIB command that I send I've found that I then need to send an RE (reset) command. If I Don't send RE the instrument takes no readings and has a blank display. For example I send FN9 to select period and get no readings until RE is sent. Is this normal? I'm currently talking to it with a USB to GPIB adapter and a terminal program. Since I had no idea if the GPIB interface was functional I didn't want to buy an expensive GPIB adapter. I build the cheapest GPIB adapter that I could find on the internet. It's possible that this is causing problems. It emulates a Prologix adapter. Here is a link if you're interested. HTTP://http://www.dalton.ax/gpib/ I've found that this adapter does not properly report the serial control line status. Because of this, Timelab won't detect the GPIB adapter. You can get Timelab to work if you choose the Acquire from counter in talk only mode option. -- Luke Mester http://mesterhome.com/ ___ 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.
