Slow ReadAsync from HP 34401 in AC mode. Works great in DC

[kb8tl]

The HP 34401 in AC mode appears to read about 4 or 5 readings per second to it's display (not online). Using MeasurementStudio's write and read async methods, the DVM's output slows to about 1 reading per second, a bit too slow for my app.

If the DVM is in DC mode, there appears to be no change in speed when on or off line. I've tried turning off the DVM's autorange and autozero to no avail.

thanks

Bob

[kb8tl]

Ooops, I forgot to mention I'm using via GPIB

Bob

[TobyHex]

Hey KB8TL,

Thanks for the update on the instrument communication! As for the read speed differences, strangley enough the HP manual for this device claims faster write speeds when the onboard monitor is off. Does your 34401 allow for this operation? It seems all is ok with the GPIB device as you are getting proper communication to the device in DC mode. The limiting factor  ultimately will be the 34401, not the GPIB card that you are using, so it would help to check with HP on recommendations on getting their device to communicate faster. Thanks again and have a great day!

Regards,

Nicholas K

[kb8tl]

Nicholas K,

Thanks for reply. I found that the 34401's trigger delay was causing my issues. It's normal automatic mode was picking a value unnecessarily long for my app. After changing it to 200 mS, the turn around time for a measurement has dropped to around 220 mS.

Bob

[TobyHex]

Hey KB8TL,

I am glad to hear that you are getting closer to normal measurements. In the future if you ever need our help with your GPIB, please feel free to contact us on the discussion forums or at the following link. Take care and have a good day! Request Support fromNational Instruments

Regards,

Nicholas K