GPIB/ENET-100 fails to send commands

[ABeard]

I'm using the GPIB/ENET-100 controller to control a Phase Matrix freq meter and a Giga-tronics power meter to measure freq and power for multiple transmitters.  The OS is VxWorks.

I can see the messages going over the network to the GPIB/ENET controller but don't see the commands coming out on the GPIB.  This is only a problem for some transmitters and none of the transmitters are controlled using GPIB commands so I know it's not an issue with GPIB addresses.

I can see UNT and UNL messages but not the ASCII strings I'm sending over.  The controller is timing out after the default 10 seconds.  I know the transmitter I'm talking to is sick so the power is probably pretty low.  I would expect the meters to return low or no readings but I don't understand why the commands wouldn't even show up on the GPIB bus.  I can't even send out commands to set up the meters.

[ScottieB]

We've never written a VxWorks driver for the GPIB-ENET/100 as far as I can remember.  Where did you get this driver?

Scott B.
GPIB Software
National Instruments

[ABeard]

You don't really sell a driver but you do sell an ESP-488 source package that can be used as the starting point for C code to commuicate with the GPIB/ENET controller.

[ScottieB]

As you know, the ESP-488 allows you to modify a lot of different source.  Are you sure that you haven't modified anything in the ESP-488 code that changed what was being sent to the GPIB-ENET/100?  Since this driver does contain non-NI code, we need to narrow it down to see if you're having issues with some of the NI-code or with the part that you or someone in your organization has written.  Can you give me a more specific description of what you're seeing or what you don't see?  What gpib calls do you make, and what do those calls put out on the GPIB bus?

Scott B.
GPIB Software
National Instruments

[ABeard]

I'm not sure how much of the original code has been changed cause I can't find the disks to compare it to.  However, the code works fine most of the time when the signal being monitored is a known good signal.  In the cases where this problem occurs, it appears that the power meter and/or frequency counter is not triggering on the signal.  It could be that they're not playing nice on the bus.  I'm currently trying to be a little smarter in our code.  I'm trying to have the meters tell me when they're done with their measurement.  I'm currently trying to figure out how to use the *SRE command.

When I get it all back working somewhat, then I'll be able to gather some more data.