How do I extend the functionality of the hp34420a driver so I can modify the NPLC (integration time) parameter to a value of 200??

[Bill.Garcia]

I am trying to configure this meter for DC volt mode and 7.5 digit and NPLC 200 settings with hp34420a 2.0 drivers in LabView 5.1. The drivers appear to limit the configuration to 6.5 digit and NPLC 10 (default) maximums.

An attempt at modifying the strings in the HP34420A Config Measurement.vi with the string ":SENS:VOLT:DC:NPLC 200" caused a timeout failure in the HP34420A Read Meas.vi, which was not recoverable by simply removing the offending sub-string in the first VI.

This program is in the latter stages of development, so a method or technique that will allow the incorporation this configuration of the HP 3
4420A, and that will extend the default timeouts in HP34420A Read Meas.vi so that readings can be obtained in the program under this configuration, is sorely needed.

Thanks.

[rtamblin]

Bill,

We normally do not support modifications to our instrument drivers, but we can give suggestions. The driver that you describe in your question must be one of our Legacy drivers, and unfortunately we do not have those available any longer. I would recommend downloading the updated IVI driver for the HP34420A from our Developer Zone site at

http://zone.ni.com/idnet97.nsf/browse/

Just do a search for 34420A and you will bring up the link to the download. You will need our IVI Engine 1.5 and VISA 2.0.1, which you will find links to there as well. The IVI driver should allow you to make the adjustments to the NPLC and DC volt mode.

Ryan Tamblin
Applications Engineer
National Instruments