Re: [AFMUG] OT odd data connection
Ok, to clarify a few things about RS-485/modbus. RS-485 is a multidrop, balanced, async serial bus, designed to run for fairly long distances over a single 120 ohms twisted pair. General you're going to have A and B which are the data lines (complimentary), and some sort of third wire which is reference (labeled something like Common, or GND, or something else). If it's RS-485 there are various RS-485 to serial USB devices out there, some isolated. If I was told that it *was* RS-485, I would suspect the two +5 low current lines are actually A and B, and the +5 and GND are there to power the cable and act as the 'C' wire as well. Modbus is just a serial protocol which runs on top of a serial bus, typically RS-485. It's usually RTU which means binary. It's a pain in the rear to write since as someone else mentioned, there are timing commitments to make, although it isn't as fussy as one would expect from reading the spec.There are also typically standardized values you can read to get the manufacturer. However, the protocol itself doesn't carry any data about what the actual data values are or where they can be found. This needs to come in the form of documentation from the vendor. On Wed, Aug 19, 2020 at 10:27 AM wrote: > On one of my large portable air compressors, there is a data port. They > sell an adapter cable for about $200 It adapts it to USB. The program > that you use to talk to it makes reference to modbus. > > The data port has 4 pins. RJ-10 4p4c connector. > +5 with enough current to light an incandescent light bulb. > +5 low current > +5 low current > Ground > > This sounds like USB host to me. One of my sons think it is RS-485 > > I don’t think USB would be happy on a RJ-10 and utp wire. Maybe it > would. Maybe I am just buying a piece of wire with two connectors on the > ends. > > The controller it plugs into is $2000 so I don’t want to experiment on > that. Be interesting to see the adapter cable when it gets here. See if > there are any active components. I would have probably just wired it up to > a USB and tried it if my son had not made the modbus/RS485 comment. > > Any guesses? > -- > AF mailing list > AF@af.afmug.com > http://af.afmug.com/mailman/listinfo/af_af.afmug.com > -- - Forrest -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com
Re: [AFMUG] OT odd data connection
Probably a lot less expensive than Prosoft Modbus products On Wed, Aug 19, 2020, 5:46 PM Matt Corcoran wrote: > Not quite related, but I just found out that Microtik(linux) has built in > drivers for common Arduino serial chips. I setup an Arduino to monitor > 4 different voltages at our solar site. Our NMS just SSHs to the > microtik(special login) to pull the average voltages and graph them.I > was happy to not add any more equipment other than the power sipping > Arduino. > > > > > > > > *Matt Corcoran* | Network Engineer > > m...@stratospeed.com | 231-680-0062 > > > > [image: signature_1101261039] <http://stratospeed.com/index.html> > > > > www.stratospeed.com|231-774-2112 > > > > > > > > > > > > *From: *AF on behalf of dave < > dmilho...@wletc.com> > *Reply-To: *AnimalFarm Microwave Users Group > *Date: *Wednesday, August 19, 2020 at 4:19 PM > *To: *"af@af.afmug.com" > *Subject: *Re: [AFMUG] OT odd data connection > > > > Ive done alot with Modbus on arduino products interfacing with anything > that speaks modbus. > I have a server I que or add each thing I want to monitor or review. > Temps, Humidity power levels or presence of are the main ones. > > > On 8/19/20 11:26 AM, ch...@wbmfg.com wrote: > > On one of my large portable air compressors, there is a data port. They > sell an adapter cable for about $200 It adapts it to USB. The program > that you use to talk to it makes reference to modbus. > > > > The data port has 4 pins. RJ-10 4p4c connector. > > +5 with enough current to light an incandescent light bulb. > > +5 low current > > +5 low current > > Ground > > > > This sounds like USB host to me. One of my sons think it is RS-485 > > > > I don’t think USB would be happy on a RJ-10 and utp wire. Maybe it > would. Maybe I am just buying a piece of wire with two connectors on the > ends. > > > > The controller it plugs into is $2000 so I don’t want to experiment on > that. Be interesting to see the adapter cable when it gets here. See if > there are any active components. I would have probably just wired it up to > a USB and tried it if my son had not made the modbus/RS485 comment. > > > > Any guesses? > > > > > > -- > AF mailing list > AF@af.afmug.com > http://af.afmug.com/mailman/listinfo/af_af.afmug.com > -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com
Re: [AFMUG] OT odd data connection
typically how you talk to solar charge controllers... On 8/19/20 5:40 PM, Mark Radabaugh wrote: Cool - it’s still around: https://modbus.org/docs/PI_MBUS_300.pdf ASCII is easy to build, RTU a little tougher due to the timing requirements. This brings back some memories… probably happily forgotten. The protocol was originally designed for talking to Modicon Programmable Logic Controllers. The documentation has lots of references to specific controllers like 384, 484, 984, etc. Read Coil, Read Input, Force Coil, etc. all refer to reading or setting an individual real world input/output or storage bit on or off. Registers are words (integers normally, but can be anything). You need detailed descriptions of the mapping of addresses on the devices you want to control to be able to understand what you are controlling. Mark On Aug 19, 2020, at 7:45 PM, Matt Corcoran <mailto:m...@stratospeed.com>> wrote: Not quite related, but I just found out that Microtik(linux) has built in drivers for common Arduino serial chips. I setup an Arduino to monitor 4 different voltages at our solar site. Our NMS just SSHs to the microtik(special login) to pull the average voltages and graph them. I was happy to not add any more equipment other than the power sipping Arduino. *Matt Corcoran* | Network Engineer m...@stratospeed.com <mailto:m...@stratospeed.com> | 231-680-0062 <http://stratospeed.com/index.html> www.stratospeed.com <http://www.stratospeed.com/> | 231-774-2112 *From:*AF mailto:af-boun...@af.afmug.com>> on behalf of dave mailto:dmilho...@wletc.com>> *Reply-To:*AnimalFarm Microwave Users Group <mailto:af@af.afmug.com>> *Date:*Wednesday, August 19, 2020 at 4:19 PM *To:*"af@af.afmug.com <mailto:af@af.afmug.com>" <mailto:af@af.afmug.com>> *Subject:*Re: [AFMUG] OT odd data connection Ive done alot with Modbus on arduino products interfacing with anything that speaks modbus. I have a server I que or add each thing I want to monitor or review. Temps, Humidity power levels or presence of are the main ones. On 8/19/20 11:26 AM,ch...@wbmfg.com <mailto:ch...@wbmfg.com>wrote: On one of my large portable air compressors, there is a data port. They sell an adapter cable for about $200 It adapts it to USB. The program that you use to talk to it makes reference to modbus. The data port has 4 pins. RJ-10 4p4c connector. +5 with enough current to light an incandescent light bulb. +5 low current +5 low current Ground This sounds like USB host to me. One of my sons think it is RS-485 I don’t think USB would be happy on a RJ-10 and utp wire. Maybe it would. Maybe I am just buying a piece of wire with two connectors on the ends. The controller it plugs into is $2000 so I don’t want to experiment on that. Be interesting to see the adapter cable when it gets here. See if there are any active components. I would have probably just wired it up to a USB and tried it if my son had not made the modbus/RS485 comment. Any guesses? -- AF mailing list AF@af.afmug.com <mailto:AF@af.afmug.com> http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com
Re: [AFMUG] OT odd data connection
Cool - it’s still around: https://modbus.org/docs/PI_MBUS_300.pdf <https://modbus.org/docs/PI_MBUS_300.pdf> ASCII is easy to build, RTU a little tougher due to the timing requirements. This brings back some memories… probably happily forgotten. The protocol was originally designed for talking to Modicon Programmable Logic Controllers.The documentation has lots of references to specific controllers like 384, 484, 984, etc. Read Coil, Read Input, Force Coil, etc. all refer to reading or setting an individual real world input/output or storage bit on or off. Registers are words (integers normally, but can be anything). You need detailed descriptions of the mapping of addresses on the devices you want to control to be able to understand what you are controlling. Mark > On Aug 19, 2020, at 7:45 PM, Matt Corcoran wrote: > > Not quite related, but I just found out that Microtik(linux) has built in > drivers for common Arduino serial chips. I setup an Arduino to monitor 4 > different voltages at our solar site. Our NMS just SSHs to the > microtik(special login) to pull the average voltages and graph them.I was > happy to not add any more equipment other than the power sipping Arduino. > > > > Matt Corcoran | Network Engineer > m...@stratospeed.com <mailto:m...@stratospeed.com> | 231-680-0062 > > <http://stratospeed.com/index.html> > > www.stratospeed.com <http://www.stratospeed.com/>|231-774-2112 > > > > > > From: AF mailto:af-boun...@af.afmug.com>> on behalf > of dave mailto:dmilho...@wletc.com>> > Reply-To: AnimalFarm Microwave Users Group <mailto:af@af.afmug.com>> > Date: Wednesday, August 19, 2020 at 4:19 PM > To: "af@af.afmug.com <mailto:af@af.afmug.com>" <mailto:af@af.afmug.com>> > Subject: Re: [AFMUG] OT odd data connection > > Ive done alot with Modbus on arduino products interfacing with anything that > speaks modbus. > I have a server I que or add each thing I want to monitor or review. > Temps, Humidity power levels or presence of are the main ones. > > > > > On 8/19/20 11:26 AM, ch...@wbmfg.com <mailto:ch...@wbmfg.com> wrote: >> On one of my large portable air compressors, there is a data port. They >> sell an adapter cable for about $200 It adapts it to USB. The program that >> you use to talk to it makes reference to modbus. >> >> The data port has 4 pins. RJ-10 4p4c connector. >> +5 with enough current to light an incandescent light bulb. >> +5 low current >> +5 low current >> Ground >> >> This sounds like USB host to me. One of my sons think it is RS-485 >> >> I don’t think USB would be happy on a RJ-10 and utp wire. Maybe it would. >> Maybe I am just buying a piece of wire with two connectors on the ends. >> >> The controller it plugs into is $2000 so I don’t want to experiment on that. >> Be interesting to see the adapter cable when it gets here. See if there >> are any active components. I would have probably just wired it up to a USB >> and tried it if my son had not made the modbus/RS485 comment. >> >> Any guesses? >> >> > > > -- > AF mailing list > AF@af.afmug.com <mailto:AF@af.afmug.com> > http://af.afmug.com/mailman/listinfo/af_af.afmug.com > <http://af.afmug.com/mailman/listinfo/af_af.afmug.com> -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com
Re: [AFMUG] OT odd data connection
Not quite related, but I just found out that Microtik(linux) has built in drivers for common Arduino serial chips. I setup an Arduino to monitor 4 different voltages at our solar site. Our NMS just SSHs to the microtik(special login) to pull the average voltages and graph them.I was happy to not add any more equipment other than the power sipping Arduino. Matt Corcoran | Network Engineer m...@stratospeed.com | 231-680-0062 [signature_1101261039]<http://stratospeed.com/index.html> www.stratospeed.com|231-774-2112 From: AF on behalf of dave Reply-To: AnimalFarm Microwave Users Group Date: Wednesday, August 19, 2020 at 4:19 PM To: "af@af.afmug.com" Subject: Re: [AFMUG] OT odd data connection Ive done alot with Modbus on arduino products interfacing with anything that speaks modbus. I have a server I que or add each thing I want to monitor or review. Temps, Humidity power levels or presence of are the main ones. [cid:image002.jpg@01D67661.4C1DE060] On 8/19/20 11:26 AM, ch...@wbmfg.com<mailto:ch...@wbmfg.com> wrote: On one of my large portable air compressors, there is a data port. They sell an adapter cable for about $200 It adapts it to USB. The program that you use to talk to it makes reference to modbus. The data port has 4 pins. RJ-10 4p4c connector. +5 with enough current to light an incandescent light bulb. +5 low current +5 low current Ground This sounds like USB host to me. One of my sons think it is RS-485 I don’t think USB would be happy on a RJ-10 and utp wire. Maybe it would. Maybe I am just buying a piece of wire with two connectors on the ends. The controller it plugs into is $2000 so I don’t want to experiment on that. Be interesting to see the adapter cable when it gets here. See if there are any active components. I would have probably just wired it up to a USB and tried it if my son had not made the modbus/RS485 comment. Any guesses? -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com
Re: [AFMUG] OT odd data connection
RS-485 is current loop rather than voltage. Easily converted to RS-232 and back. Modbus is a communication protocol using formatted text strings. It’s pretty simple to read and write programatically.I have written a few BASIC programs to do so (I date myself). Any programming language that can process text strings can speak Modbus with a little work. Modbus+ is a higher speed synchronously timed protocol that is considerably more involved to work with. Mark > On Aug 19, 2020, at 4:29 PM, ch...@wbmfg.com wrote: > > It is a way to get in and set parameters and options, like remote start or > remote loading. > > From: Cameron Crum <> > Sent: Wednesday, August 19, 2020 1:57 PM > To: AnimalFarm Microwave Users Group <> > Subject: Re: [AFMUG] OT odd data connection > > Just curious what kind of data you need for an air compressor? > > On Wed, Aug 19, 2020 at 11:51 AM TJ Trout > wrote: >> apc uses rj10's for usb.. >> >> On Wed, Aug 19, 2020 at 9:46 AM Ken Hohhof > wrote: >>> Apparently modbus is a data protocol, not a physical layer standard, but >>> yes it could go over RS485. I don’t see how a simple cable could convert >>> from USB to RS485. I sure hope for $200 you are getting a dongle, not an >>> expensive cable. >>> >>> The connector you are referring to, is that a 4 pin modular plug, like used >>> on the handset cord for a phone? >>> >>> From: AF > On Behalf Of ch...@wbmfg.com <> >>> Sent: Wednesday, August 19, 2020 11:27 AM >>> To: af@af.afmug.com <> >>> Subject: [AFMUG] OT odd data connection >>> >>> On one of my large portable air compressors, there is a data port. They >>> sell an adapter cable for about $200 It adapts it to USB. The program >>> that you use to talk to it makes reference to modbus. >>> >>> The data port has 4 pins. RJ-10 4p4c connector. >>> +5 with enough current to light an incandescent light bulb. >>> +5 low current >>> +5 low current >>> Ground >>> >>> This sounds like USB host to me. One of my sons think it is RS-485 >>> >>> I don’t think USB would be happy on a RJ-10 and utp wire. Maybe it would. >>> Maybe I am just buying a piece of wire with two connectors on the ends. >>> >>> The controller it plugs into is $2000 so I don’t want to experiment on >>> that. Be interesting to see the adapter cable when it gets here. See if >>> there are any active components. I would have probably just wired it up to >>> a USB and tried it if my son had not made the modbus/RS485 comment. >>> >>> Any guesses? >>> -- >>> AF mailing list >>> AF@af.afmug.com <> >>> http://af.afmug.com/mailman/listinfo/af_af.afmug.com >>> <http://af.afmug.com/mailman/listinfo/af_af.afmug.com> >> -- >> AF mailing list >> AF@af.afmug.com <> >> http://af.afmug.com/mailman/listinfo/af_af.afmug.com >> <http://af.afmug.com/mailman/listinfo/af_af.afmug.com> > > > -- > AF mailing list > AF@af.afmug.com > http://af.afmug.com/mailman/listinfo/af_af.afmug.com > -- > AF mailing list > AF@af.afmug.com > http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com
Re: [AFMUG] OT odd data connection
It is a way to get in and set parameters and options, like remote start or remote loading. From: Cameron Crum Sent: Wednesday, August 19, 2020 1:57 PM To: AnimalFarm Microwave Users Group Subject: Re: [AFMUG] OT odd data connection Just curious what kind of data you need for an air compressor? On Wed, Aug 19, 2020 at 11:51 AM TJ Trout wrote: apc uses rj10's for usb.. On Wed, Aug 19, 2020 at 9:46 AM Ken Hohhof wrote: Apparently modbus is a data protocol, not a physical layer standard, but yes it could go over RS485. I don’t see how a simple cable could convert from USB to RS485. I sure hope for $200 you are getting a dongle, not an expensive cable. The connector you are referring to, is that a 4 pin modular plug, like used on the handset cord for a phone? From: AF On Behalf Of ch...@wbmfg.com Sent: Wednesday, August 19, 2020 11:27 AM To: af@af.afmug.com Subject: [AFMUG] OT odd data connection On one of my large portable air compressors, there is a data port. They sell an adapter cable for about $200 It adapts it to USB. The program that you use to talk to it makes reference to modbus. The data port has 4 pins. RJ-10 4p4c connector. +5 with enough current to light an incandescent light bulb. +5 low current +5 low current Ground This sounds like USB host to me. One of my sons think it is RS-485 I don’t think USB would be happy on a RJ-10 and utp wire. Maybe it would. Maybe I am just buying a piece of wire with two connectors on the ends. The controller it plugs into is $2000 so I don’t want to experiment on that. Be interesting to see the adapter cable when it gets here. See if there are any active components. I would have probably just wired it up to a USB and tried it if my son had not made the modbus/RS485 comment. Any guesses? -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com
Re: [AFMUG] OT odd data connection
Ive done alot with Modbus on arduino products interfacing with anything that speaks modbus. I have a server I que or add each thing I want to monitor or review. Temps, Humidity power levels or presence of are the main ones. On 8/19/20 11:26 AM, ch...@wbmfg.com wrote: On one of my large portable air compressors, there is a data port. They sell an adapter cable for about $200 It adapts it to USB. The program that you use to talk to it makes reference to modbus. The data port has 4 pins. RJ-10 4p4c connector. +5 with enough current to light an incandescent light bulb. +5 low current +5 low current Ground This sounds like USB host to me. One of my sons think it is RS-485 I don’t think USB would be happy on a RJ-10 and utp wire. Maybe it would. Maybe I am just buying a piece of wire with two connectors on the ends. The controller it plugs into is $2000 so I don’t want to experiment on that. Be interesting to see the adapter cable when it gets here. See if there are any active components. I would have probably just wired it up to a USB and tried it if my son had not made the modbus/RS485 comment. Any guesses? -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com
Re: [AFMUG] OT odd data connection
Just curious what kind of data you need for an air compressor? On Wed, Aug 19, 2020 at 11:51 AM TJ Trout wrote: > apc uses rj10's for usb.. > > On Wed, Aug 19, 2020 at 9:46 AM Ken Hohhof wrote: > >> Apparently modbus is a data protocol, not a physical layer standard, but >> yes it could go over RS485. I don’t see how a simple cable could convert >> from USB to RS485. I sure hope for $200 you are getting a dongle, not an >> expensive cable. >> >> >> >> The connector you are referring to, is that a 4 pin modular plug, like >> used on the handset cord for a phone? >> >> >> >> *From:* AF *On Behalf Of *ch...@wbmfg.com >> *Sent:* Wednesday, August 19, 2020 11:27 AM >> *To:* af@af.afmug.com >> *Subject:* [AFMUG] OT odd data connection >> >> >> >> On one of my large portable air compressors, there is a data port. They >> sell an adapter cable for about $200 It adapts it to USB. The program >> that you use to talk to it makes reference to modbus. >> >> >> >> The data port has 4 pins. RJ-10 4p4c connector. >> >> +5 with enough current to light an incandescent light bulb. >> >> +5 low current >> >> +5 low current >> >> Ground >> >> >> >> This sounds like USB host to me. One of my sons think it is RS-485 >> >> >> >> I don’t think USB would be happy on a RJ-10 and utp wire. Maybe it >> would. Maybe I am just buying a piece of wire with two connectors on the >> ends. >> >> >> >> The controller it plugs into is $2000 so I don’t want to experiment on >> that. Be interesting to see the adapter cable when it gets here. See if >> there are any active components. I would have probably just wired it up to >> a USB and tried it if my son had not made the modbus/RS485 comment. >> >> >> >> Any guesses? >> -- >> AF mailing list >> AF@af.afmug.com >> http://af.afmug.com/mailman/listinfo/af_af.afmug.com >> > -- > AF mailing list > AF@af.afmug.com > http://af.afmug.com/mailman/listinfo/af_af.afmug.com > -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com
Re: [AFMUG] OT odd data connection
apc uses rj10's for usb.. On Wed, Aug 19, 2020 at 9:46 AM Ken Hohhof wrote: > Apparently modbus is a data protocol, not a physical layer standard, but > yes it could go over RS485. I don’t see how a simple cable could convert > from USB to RS485. I sure hope for $200 you are getting a dongle, not an > expensive cable. > > > > The connector you are referring to, is that a 4 pin modular plug, like > used on the handset cord for a phone? > > > > *From:* AF *On Behalf Of *ch...@wbmfg.com > *Sent:* Wednesday, August 19, 2020 11:27 AM > *To:* af@af.afmug.com > *Subject:* [AFMUG] OT odd data connection > > > > On one of my large portable air compressors, there is a data port. They > sell an adapter cable for about $200 It adapts it to USB. The program > that you use to talk to it makes reference to modbus. > > > > The data port has 4 pins. RJ-10 4p4c connector. > > +5 with enough current to light an incandescent light bulb. > > +5 low current > > +5 low current > > Ground > > > > This sounds like USB host to me. One of my sons think it is RS-485 > > > > I don’t think USB would be happy on a RJ-10 and utp wire. Maybe it > would. Maybe I am just buying a piece of wire with two connectors on the > ends. > > > > The controller it plugs into is $2000 so I don’t want to experiment on > that. Be interesting to see the adapter cable when it gets here. See if > there are any active components. I would have probably just wired it up to > a USB and tried it if my son had not made the modbus/RS485 comment. > > > > Any guesses? > -- > AF mailing list > AF@af.afmug.com > http://af.afmug.com/mailman/listinfo/af_af.afmug.com > -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com
Re: [AFMUG] OT odd data connection
Yes, I actually found an old phone and was in the process of hacking up a converter cable when my sons talked me out of connecting it. From: Ken Hohhof Sent: Wednesday, August 19, 2020 10:45 AM To: 'AnimalFarm Microwave Users Group' Subject: Re: [AFMUG] OT odd data connection Apparently modbus is a data protocol, not a physical layer standard, but yes it could go over RS485. I don’t see how a simple cable could convert from USB to RS485. I sure hope for $200 you are getting a dongle, not an expensive cable. The connector you are referring to, is that a 4 pin modular plug, like used on the handset cord for a phone? From: AF On Behalf Of ch...@wbmfg.com Sent: Wednesday, August 19, 2020 11:27 AM To: af@af.afmug.com Subject: [AFMUG] OT odd data connection On one of my large portable air compressors, there is a data port. They sell an adapter cable for about $200 It adapts it to USB. The program that you use to talk to it makes reference to modbus. The data port has 4 pins. RJ-10 4p4c connector. +5 with enough current to light an incandescent light bulb. +5 low current +5 low current Ground This sounds like USB host to me. One of my sons think it is RS-485 I don’t think USB would be happy on a RJ-10 and utp wire. Maybe it would. Maybe I am just buying a piece of wire with two connectors on the ends. The controller it plugs into is $2000 so I don’t want to experiment on that. Be interesting to see the adapter cable when it gets here. See if there are any active components. I would have probably just wired it up to a USB and tried it if my son had not made the modbus/RS485 comment. Any guesses? -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com
Re: [AFMUG] OT odd data connection
Apparently modbus is a data protocol, not a physical layer standard, but yes it could go over RS485. I don’t see how a simple cable could convert from USB to RS485. I sure hope for $200 you are getting a dongle, not an expensive cable. The connector you are referring to, is that a 4 pin modular plug, like used on the handset cord for a phone? From: AF On Behalf Of ch...@wbmfg.com Sent: Wednesday, August 19, 2020 11:27 AM To: af@af.afmug.com Subject: [AFMUG] OT odd data connection On one of my large portable air compressors, there is a data port. They sell an adapter cable for about $200 It adapts it to USB. The program that you use to talk to it makes reference to modbus. The data port has 4 pins. RJ-10 4p4c connector. +5 with enough current to light an incandescent light bulb. +5 low current +5 low current Ground This sounds like USB host to me. One of my sons think it is RS-485 I don’t think USB would be happy on a RJ-10 and utp wire. Maybe it would. Maybe I am just buying a piece of wire with two connectors on the ends. The controller it plugs into is $2000 so I don’t want to experiment on that. Be interesting to see the adapter cable when it gets here. See if there are any active components. I would have probably just wired it up to a USB and tried it if my son had not made the modbus/RS485 comment. Any guesses? -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com
Re: [AFMUG] OT odd data connection
The voltages make sense if it is TTL. From: Brian Webster Sent: Wednesday, August 19, 2020 10:34 AM To: 'AnimalFarm Microwave Users Group' Subject: Re: [AFMUG] OT odd data connection MODBUS and RS-485 are very commonly related and used together. As I remember RS-485 is just a format that goes farther distance than RS-232. This is/was typical in SCADA systems. I don’t recall if it was TTL logic levels or not. I would not be surprised if the cable is also a TTL logic converter. Jamie can probably shed a lot more light on the topic. Thank you, Brian Webster www.wirelessmapping.com From: AF [mailto:af-boun...@af.afmug.com] On Behalf Of ch...@wbmfg.com Sent: Wednesday, August 19, 2020 12:27 PM To: af@af.afmug.com Subject: [AFMUG] OT odd data connection On one of my large portable air compressors, there is a data port. They sell an adapter cable for about $200 It adapts it to USB. The program that you use to talk to it makes reference to modbus. The data port has 4 pins. RJ-10 4p4c connector. +5 with enough current to light an incandescent light bulb. +5 low current +5 low current Ground This sounds like USB host to me. One of my sons think it is RS-485 I don’t think USB would be happy on a RJ-10 and utp wire. Maybe it would. Maybe I am just buying a piece of wire with two connectors on the ends. The controller it plugs into is $2000 so I don’t want to experiment on that. Be interesting to see the adapter cable when it gets here. See if there are any active components. I would have probably just wired it up to a USB and tried it if my son had not made the modbus/RS485 comment. Any guesses? -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com
Re: [AFMUG] OT odd data connection
I never noticed, but yeah the pinout for both looks identical. I wonder if RS485 and USB have some shared heritage. The converters are very small. It might be hard to tell the difference between a slightly large plug package and a miniaturized electronic package.without cutting it open of course. Here's one from Newark: https://www.newark.com/productimages/standard/en_US/4817085.jpg On 8/19/2020 12:26 PM, ch...@wbmfg.com wrote: On one of my large portable air compressors, there is a data port. They sell an adapter cable for about $200 It adapts it to USB. The program that you use to talk to it makes reference to modbus. The data port has 4 pins. RJ-10 4p4c connector. +5 with enough current to light an incandescent light bulb. +5 low current +5 low current Ground This sounds like USB host to me. One of my sons think it is RS-485 I don’t think USB would be happy on a RJ-10 and utp wire. Maybe it would. Maybe I am just buying a piece of wire with two connectors on the ends. The controller it plugs into is $2000 so I don’t want to experiment on that. Be interesting to see the adapter cable when it gets here. See if there are any active components. I would have probably just wired it up to a USB and tried it if my son had not made the modbus/RS485 comment. Any guesses? -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com
Re: [AFMUG] OT odd data connection
MODBUS and RS-485 are very commonly related and used together. As I remember RS-485 is just a format that goes farther distance than RS-232. This is/was typical in SCADA systems. I don’t recall if it was TTL logic levels or not. I would not be surprised if the cable is also a TTL logic converter. Jamie can probably shed a lot more light on the topic. Thank you, Brian Webster www.wirelessmapping.com From: AF [mailto:af-boun...@af.afmug.com] On Behalf Of ch...@wbmfg.com Sent: Wednesday, August 19, 2020 12:27 PM To: af@af.afmug.com Subject: [AFMUG] OT odd data connection On one of my large portable air compressors, there is a data port. They sell an adapter cable for about $200 It adapts it to USB. The program that you use to talk to it makes reference to modbus. The data port has 4 pins. RJ-10 4p4c connector. +5 with enough current to light an incandescent light bulb. +5 low current +5 low current Ground This sounds like USB host to me. One of my sons think it is RS-485 I don’t think USB would be happy on a RJ-10 and utp wire. Maybe it would. Maybe I am just buying a piece of wire with two connectors on the ends. The controller it plugs into is $2000 so I don’t want to experiment on that. Be interesting to see the adapter cable when it gets here. See if there are any active components. I would have probably just wired it up to a USB and tried it if my son had not made the modbus/RS485 comment. Any guesses? -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com
