NI MAX can find the address of SR530, but no response from SR530 after sending request

[SHUEN!WEI]

Hi,

I connect Lock-in Amplifier(SR530) with GPIB.

After I scan device with Measurement&Automation, the address of instrument can be found. 23 based on the manuanal.

but as I send data request commend *Q1"or "QX"..... balala... I cannot get the value from this SR530.

I do need your help for this problem. Many THX

Best regards,

SHUEN WEI

[GerdW]

Hi Shuenwei,

can you receive an answer for the *IDN? request?

(Right inside MAX using a testpanel…)

[SHUEN!WEI]

No. I think SR530 is too old and cant identify the command "*IDN?", while NI MAX can find the address of SR530.

Best regards,

Shuen Wei

[billko]

Communications is probably much easier using the serial interface.

[rolfk]

The SR5xx series are very old devices. The used GPIB controller (MC68488) in there is not implementing GPIB according to the more modern standard IEEE488.2. This means you will have to play a bit with the low level settings of the GPIB interface in NI-488.2 to get it to work. I'm not sure about the exact details anymore (this was around 1994 when I worked at NI in Application Engineering) but Enable Readdressing and such options might be involved. Also the MC68488 has a timing bug in its handling of the GPIB signals that violates the GPIB specs. Solution was to add an extra capacitor to one of the handshake lines to slow down that signal a bit, so that it can work with standard compliant controllers such as all NI GPIB controllers. Early versions of the Stanford Research devices all required to be opened and modified to add this capacitor on the PCB to make it work with NI high speed capable GPIB controllers. Later versions should contain this modification out of the box.

The Motorola MC68488 isn't manufactured nowadays and newer models like the SR8xx series and similar will use different controller chips to implement GPIB functionality and should not have any of these problems. RS-232 connectivity may indeed be the better option but will come with its own challenges that are inherent to RS-232 operation.