Cryogenic SMS120C superconducting magnet power supply

[AKHuettel]

Dear all,

has anyone here had success in accessing the aforementioned "Cryogenic SMS120C superconducting magnet power supply" with LabView, and would be willing to give some hints / maybe even share the code?

For details about the device, see the manufacturer website.

It seems to be pretty trivial to send commands to the power supply - WriteGPIB does the job and the device responds. However I have not managed to get any status information / command output back; when I do a subsequent ReadGPIB, I always get only an empty line. ???

Thanks in advance for any hints;
best, Andreas

[Albert.Geven]

Hi Andreas

The manual is very good
What did you send before the read gpib?

[AKHuettel]

Hi Albert,

e.g. I use "GPIB Write" to send "UPDATE"+CRLF to the device. I tested both having a string constant

"UPDATE

"

and sending it with mode "0" , and removing the newline from the constant and using mode "3" or "6" of the GPIB Write vi.

The write succeeds this way. (And if I use another command instead, e.g. "PAUSE 1", I see the corresponding LED go on on the (hardware) front panel of the device accordingly. So the device receives and processes the command.)

Now, UPDATE should according to the manual give a lot of text. So immediately afterwards (next page of a stacked sequence) I call "GPIB Read" with the same GPIB address, number of bytes 200, timeout e.g. 1000ms.

For any "mode" parameter to "GPIB Read" except "2" and "10" I get a timeout and no data read (empty string).

For "mode" equal "2" or "10", a string containing a single linefeed (1 character) is returned.

This is how far I got, any further experimenting did not help...

Could it be that the device first outputs a blank line and then something else? I dont think so, since I tried also multiple subsequent read commands (copied the page of the stacked sequence), but they all give blank lines, or sometimes errors if the commands follow each other too fast (I think).

Best, Andreas

[Albert.Geven]

Hi

try this with VISA write and read.
I agree that update should give more data.
The only thing I could not check in your email is if you are really sending CR and LF.
try to put your command in a string indicator and change the display mode into "\"Codes Display.

For VISa you only nead the visa write followed by the visa read.
Opening and closing are not necessary anymore.
To find your instruments visa resource name just click on the small triangle on the right of the visa resource name control
that you get when creating a control on the visa write function input

[AKHuettel]

Hi Albert,

I tried the same with VISA calls and ended up with the same result. Timeouts for normal reads; when I set the termination character property to ASCII 10, I get empty lines and sometimes errors. Writing works and the device executes the commands. I started playing around a lot with the NI VISA tool for adressing devices - with the same results.

By now I suspect that this may be a hardware issue with the power supply, since I checked old "working" revisions of the control software and they still contain output from the power supply in the labview indicators (and it looks exactly as in the manual). I cannot power-cycle the device now; too much sensitive stuff on the same mains circuit. I'll try that later though, maybe it resolves the issue.

Best, Andreas

[Albert.Geven]

Hi Andreas

maybe your gpib is simply too fast. Oficially it is a handshake bus so no timing problems but if you have an old machine, the default speed maybe too fast.
I mostly set the bus handshake speed to 2.5 useconds (the slowest option on the gpib settings)
I also disable autoserial poll because I don't want to miss a poll.

good luck

[Dumbell]

I have been asked to use this power supply in a new experiment.

Is there an update to this thread - does this work correctly?

Thank you,