CMU 200 error

[vivek_sony]

I am trying to run one of the Driver VIs of the CMU200 in LABview. But everytime I run it, it gives an error "The given session or object reference is invalid." The measurement and Automation Explorer shows the CMU200 and I am also able to comminucate with the device, by right clicking on it. Any suggestions?

[vivek_sony]

If anybody has worked or working with drivers of CMU 200 in LABview, let me know. I am finding a hard time in dealing with the drivers.

[ian_fung]

Did you pass in the VISA session (to the driver VI) correctly?

[vivek_sony]

I am using RSCMU_Init_GSM_sig.vi to initialize the operation. One of the connector of the VI is "BASE VISA Session". I am giving address here as GPIB0::20::0::INSTR (which is of CMU 200 ans is correct). Still cant figure out?

[TongY]

The device descriptor you used "GPIB0::20::0::INSTR" seems to be the default value used in the driver vis, is the primary address of the instrument really 20 and secondary address 0? If you do not need to use secondary address, you don't have to use any value for this part. Please check the dip-switches on other instruments to make sure not another device is using the same address. You can also try to assign a different address to the device.

Can you communicate to the instrument just using NI-VISA function? Can you do a query in MAX? Both methods are simple ways to establish communications with your instrument.

[vivek_sony]

yeah I am able to Query the device by MAX. I checked the address, it is correct. Also, whenever I restart the LABview and open the VI that initiates the device, the device do go in remote mode but no further communication happens and the VI keep giving the same error.

[vivek_sony]

Also I am attaching the NI spy snapshot.

[Aaron_G]

Make sure that when you open the device that the ID Query input is set to true. The R&S CMU driver (dll) caches the firmware version of the CMU, if a command does not match the minimum firmware revision, you will get an error. If you do not query the instrument when you open it, the firmware is treated as 0 and all subsequent commands will error with an insufficient firmware revision error message.

Regards,
Aaron

[TongY]

Looks like you are setting certain Attribute Event to False, that event could be something like ID Query. You need to change it to true to initialize the devices.