R&S CMU200 GPIB/COM communication problems - Page 1
Forum section: electronics / rf-microwave

author: Decee1
author_rank: Regular Contributor
timestamp: August 28, 2021, 04:02:23 pm
content: Hello,I own a CMU200 where I would like to access it from my computer. I own a china prologix and a USB Serial adapter.I tried both of them but I am not getting any response at all.If I enable debug mode it also doesn't even enter remote access.Anyone faced this issue who can share their experience?

author: Decee1
author_rank: Regular Contributor
timestamp: August 28, 2021, 11:47:43 pm
content: Still no luck, I've found another thread where he mentions that he also got one of the GPIB adapters as I got but it works for him, weird why mine doesn't work!Thread I'm talking about:https://www.eevblog.com/forum/rf-microwave/rs-cmu200-gpib-prologix-problem/

author: Decee1
author_rank: Regular Contributor
timestamp: August 30, 2021, 08:43:56 pm
content: I've gotten it to enter remote mode a few times but i think it is totally random.But what I've figured out is that when you enter remote mode and tries to go to local it seems to be busy all the time on the remote, so it might seem like something is interrupting the remote interrupt and therefor cannot recieve data?

author: Decee1
author_rank: Regular Contributor
timestamp: August 30, 2021, 08:53:51 pm
content: I GOT IT WORKING WITH SERIAL!!Don't trust those F**king serial cable extentions from china..Tho i still need to get the GPIB Prologix working, but 1 step at a time

author: Decee1
author_rank: Regular Contributor
timestamp: August 30, 2021, 10:38:56 pm
content: So I've managed to get the GPIB sending data.With Primary address set to 0 and the secondary address 1 on the instrumentPrologix address: "++addr 0 97"and the write "*idn?" i can see on the CMU200 that it receives the data and transfer the correct answerBut if i then write "++read eoi" it returns nothing.If i connect it to my Agilent instrument and write "READ?" and "++read eoi" it returns a result.I also tried cleaning the GPIB connector with alcohol but didn't fix anything..

author: richnormand
author_rank: Unknown
timestamp: August 30, 2021, 10:59:04 pm
content: I managed to get my CMU200 to work with a GPIB to USB from Agilent using the Keysight software, but it was not straightforward.The CMU200 is strict on the exact setup, protocol, support software and has to use primary and secondary GPIB addresses in the right configuration for each module you might want to talk to.You might need to find out if your GPIB unit is following the protocols.""With Primary address set to 0 and the secondary address 1 on the instrument""What is the address of the Prologix? Is instrument here referring to the CMU200?There are several older threads on eevblog on these subjects.As well a member here (bicurio) has a program that talks well to the GPIB and might be able to help you.You might want to look him up for the prologix.As far as RS232 it was the same deal. You have to setup the CMU200 via the config menus properly for each function. As you found out, it will respond at the lowest level but the rest will not respond if not setup properly.Best of luck with it.Cheers

author: Decee1
author_rank: Regular Contributor
timestamp: August 31, 2021, 12:04:58 am
content: Hello, thanks for your reply.Quote from: richnormand on August 30, 2021, 10:59:04 pmThe address does not matter. But I am sure that the Prologix comport is correct.Quote from: richnormand on August 30, 2021, 10:59:04 pmI have actually checked out he's Software. As it was written for Python 2.6 I had to update it to 3.6.It is facing the same issue as I am, does not receive response on "*IDN?" command.Also been reading many of the posts here, none solves my problem sadly.

author: lordium
author_rank: Regular Contributor
timestamp: August 31, 2021, 01:23:51 am
content: The primary address is the one you set in the CMU menu (20 for example), the secondary address is the one to what interface in the CMU you want to connect (could be 0,1,2,3 etc). Add 96 to the secondary address.Sec add does not work with prologix in device mode, you need to be in controller mode.According to prologix, the syntax should be "++addr 20 96" for pri 20, sec 0I personally use a gpib pci card in my pc, and the secondary is REQUIRED for it to work. Just using primary gives similar results with communication but no answer (because not reading from correct secondary address).

author: Decee1
author_rank: Regular Contributor
timestamp: August 31, 2021, 10:15:34 am
content: Quote from: lordium on August 31, 2021, 01:23:51 amSadly I'm already in controller mode,Quote from: lordium on August 31, 2021, 01:23:51 amYep! That part I have realised. If I'm in controller mode with "++addr 0 97" (for pri 0, sec 1) and I try out "*IDN?" I can see the instrument enters remote mode and I can see it receives "*IDN?" and also transfers the data but I don't receive it when i read the GPIB bufferQuote from: lordium on August 31, 2021, 01:23:51 amI do surely agree! I also prefer a GPIB PCI card or in my case a GPIB USB from NI. as I don't have any more empty PCI ports. But hey! Why upgrade if this one works! I know the USB Prologix works as it can read from my Agilent 34401A.. So something gotta be wrong with the Instruments GPIB somehow

author: Decee1
author_rank: Regular Contributor
timestamp: August 31, 2021, 02:25:09 pm
content: I've been working on making a simple tracking generator Software (not that i have any usecase but I just like having fun with programming)The comport surely works like a charm but the Prologix is not able to query.I've actually ordered a GPIB-USB-HS from china (seems to be preowned) so i can get a better test scenario and ensure it is not the Prologix causing issues.I've made a Python driver called GPIBprologix which works pretty well but not with this instrument, it also does not support secondary address which I'll have to add in the future.But surely.. After I get my GPIB-USB-HS the Prologix is not gonna be used as much as now hehe

author: lordium
author_rank: Regular Contributor
timestamp: September 01, 2021, 01:27:55 am
content: you can try "++auto 0" before querying to disable the prologix to immidietly send response, and then manually ++read after instead.Also, does ++addr show SAD after being set?I don't own a prologix, but do have a DIY version which has same protocol but custom firmware. I can try using that to try to replicate your issue this weekend if you haven't found the issue by then.