Instrument Drivers

[Troy]

I am looking for any information on controling an HP8757C Scalar Network Analyzer with a HP 8350B Sweep Oscillator. I am able to control and comunicate with the 8757 in the system, but am unable to talk to the 8350. If I connect the 8350 directly to the GPIB, I can control it, but not while it is a part of the measurement system with the 8757. Any hints or assistance would be greatly appreciated.

[Dennis_Knutson]

Have you checked and made sure that the GPIB address of the two instruments are different?

[Troy]

Yes they are different. The 8757 has GPIB address of 16, and the 8350 has GPIB address of 19. Both are the factory default.

[Troy]

Hey Dennis,
I suppose I should elaborate a little, in case you are not familar with the equipment. The 8757 and 8350 are designed to work together as a complete test set. The 8757 and 8350 communicate to each other through a GPIB cable connected to a local instrument bus off of the 8757. The 8757 is supposed to have some sort of a pass through for control of the 8350 (or at least that is what I can tell from what little documentation I have on it.) I have the list of GPIB commands used for controling both pieces of equipment, but I am unable to communicate with the 8350 through the 8757. Have you seen this type of instrument control before, and am I going to be able to control the 8350 through LabView, or will I have to have the user perform the settings of the
8350 manually?

[Dennis_Knutson]

Sorry that I misunderstood. I've never used the 8757 but I once used a different piece of HP test equipment that did something similar. I can't remember exactly what it was but do remember having to fiddle a lot with the host instrument. I remember getting some help from my local HP sales engineer. I wish I could be of more help.

[ernst]

You must first tell the Scalar Network Analyzer the address of the Signal Generator via the Pass through command. If the address of the Signal Generator is 19 then "PT19;" is the command to be used. After that any time you want to talk Generator then you must add 1 to what ever address the Scalar is set to. This is the address needed to talk to the Generator. So if the address of the Scalar is 16 then use 17 to talk to the generator. The Generator must also be hooked up to the Scalar's System Interface Bus for all of this to work.

Good luck