-1074001665

[NigelSmith]

I've developed a VI that reads the voltage from a HP34401A DMM and checks it against preset limits. As a stand alone VI it runs repeatedly with out error, however, when called from an other VI it runs the first time with out error, but reports:-

-1074001665

<ERR> HP34401A Error Query;instrument reports:-103,"Invalid separator"

on every other run of the program, has anyone seen this before and know how to resolve it?

[smercurio_fc]

That VI was not designed to be called repeatedly from a higher-level VI. The VI always opens a new VISA session and reconfigures the instrument. If you are calling this from a higher level VI then you are performing a lot of unnecessary and wasteful operations. You should separate out the VI into Open, Configure, Read, and Close. Then, call just the Read inside your loop.

[NigelSmith]

Hi Smercurio_fc

The VI is not being called repeatedly, I'm calling it once only but every secind time the VI is run, it get the error. i.e. the first run of the main VI it works fine. then when I run it again I get the error, but the third time of running the main VI it works again and so on.

[smercurio_fc · Accepted solution]

Clearly one of those VIs is sending a command the instrument doesn't like. I don't have the hp34401 library, but if I had to guess I'd say it's probably the "Control Mode" VI since that occurs after the error query, and you say it happens on every other run. I would suggest using the updated drivers found here: http://sine.ni.com/apps/utf8/niid_web_display.download_page?p_id_guid=014E7F05D12C6F8BE0440003BA7CCD....

Also, you can use the Time Delay VI for the delay, allowing you to delete the sequence structure altogether.