Opening VI block diagram engaging remote instrument control

[blockheadjr]

This is a phenomena that doesn't seem to cause any major functionality issues - but I'm still curious how opening the block diagram window of a VI can automatically engage remote control of any connected instruments that are powered up - even when the VI itself is not running?  The only problem I have with this is if manual control is needed prior to running the VI.

Has anyone else encountered this issue?

[Robert M]

I'm curious as to why this would be happening.  Why don't you try doing a spy capture using NI-SPY.  Start the capture just before you open the block diagram.  The capture should see and record any calls to the driver that would initiate communication with your instrument.  What protocol are you connected to the instrument through?

[blockheadjr]

I'm using a GPIB interface.

Here's the SPY capture:



The VI's Front Panel is already open before the capture begins.  The only action I take after starting the capture is a Ctrl+E command to open the block diagram of the program.  Once I confirmed that my instruments were in remote control, I stopped the capture.  Again, the VI is not running at the time.

[Robert M]

What, exactly, does it mean that your instrument is in remote control?  It looks like LabVIEW is querying for what instruments might be out there, but it shouldn't be causing anything to happen or taking control.

[blockheadjr]

By "remote control", I mean that the REMOTE indicator is illuminated on the instruments, and manual control is locked out.  Only Labview can control the instruments at that time.

[Robert M]

What, exactly, causes the "REMOTE" indicator on your device to come on?  It looks like if you have any VISA resource objects on your block diagram and open the block diagram, LabVIEW searches what devices are out there.  I would be surprised if your instruments reponds to a simple query by going into remote mode, but that may be what's happening.  Can you check the manual for your instrument to see what commands put the device in the remote state?

[xseadog]

hi Blockheadjr
you don't mention what version of labview you are using !!
If I can remember correctly with version 5 or 5.1 we use to have a  problem on initialisation that labview would 'take over local control of power
uped intruments connected via GPIB. It was not a problem to manually localise them.

xseadog.