LabView Infiniium Drivers unexpectedly changing scope settings

[hkeene]

I recently installed the latest LabView drivers for the Infiniium oscilloscopes. I'm trying to create a LabView program that can save XYPairs and Waveforms for each of the four channels and save a screenshot if desired. I'm using the newest software upgrade for the Infiniium's that allows GPIB commands to be issued over the LAN. All of the code works except for the HP548xx Initialize.vi or the HP548xx Initialize with Options.vi If I use either of these to initialize the communication with the scope they reset my horizontal options from center to left and the trigger mode from single to trig'd. I have tried just running this VI and it is definitely the culprit. I have also tried every combination of in
put options that I know about. My question is this: Has anyone every experienced this problem or a problem like it, or does anyone know of a place that I can find the documentation for the drivers.

[btejani]

The instrument driver you are using is an IVI driver that maintains a cache of instrument settings. It does this to optimize I/O. However, a necessary action for this functionality is that the instrument driver must set the instrument to a known state. If you download the LabWindows/CVI driver, you can take a look at the C source code, which shows that the driver always sets the Horizontal Record Reference Position to the left, the trigger modifier to trigger, Interpolation to none, and initiate continuous to false.

Some workarounds for your problem:
1) Download & install the LabVIEW traditional driver for the Infiniium scopes. That dri
ver does not support state caching and will not set the instrument to particular values.

2) Use the hp548xx driver's waveform measurement functions to retrieve the waveforms you want, and display them on the same graph in LabVIEW.

3) Turn off state caching in MAX for the hp548xx and then use the Write Instrument Data VI to set the horizontal options you want and retrieve the screen shots, etc. You can set the Trigger Modifier property to Single using a property node.