Initialize DMM with some default GPIB commands

[CHIW]

Hello,

We are using IVI in combination with teststand and labview. Now our problem occures when we communicate with our current DMM and the successor of it. The autoranging mode of the new DMM is reacting different with respect to our current DMM.

Is there a way to initialize the DMM via IVI with some default GPIB commands without making changes in labview and teststand? This because of interchangeability between our current and possible new systems.

Greetings,

C. Wong

[RikPrins]

Hello Mr. Wong,

Unfortunatly it is not that simple. Every manufacturer creates a set commands for there instruments which aply to only that instrument. They also define how the instrument reacts on the commands. It can even be the case that two instruments of the same manufacturer have different command sets or react differently on the same command.

There have been some attemts in past to standarize the commands in instrumentation but it never has been fully addopted by all instrument manufacturers. One of the best attemts was IVI which made it possible to connect different instruments that apply to the same IVI Class like DMM's and use them with the same commands. The point is that the manufacturer can still modify a function, inside the DMM slightly in newer models, which is called by the same IVI command.

What are exactly the problems you are seeing and what kind of DMMs are you using?

Regards,

RikP - National Instruments Applications Engineering

[jjp377]

Hi,

A couple of other questions

What versions of IVI Compliance Package, LabVIEW, and Teststand are you using?

What interface are using?

Are the DMMs one the same bus?

[CHIW]

Hi,

I'm now using a fluke 45 DMM, but we can't buy this anymore. So we were looking for a successor for it. THis woult be the fluke 8845A and the 8846A. These meters could be placed in fluke 45 emulation. So we did it. But there're some little differences between these meters.

This reply came from fluke: "the Fluke 45 ranges between the 100mA and 10A input terminals, while the 8845A/8846A will autorange on the selected current input terminal only".

So my question was, is it possible to send fluke 45 GPIB commands without changing anything in Labview and TestStand? (We want to use these DMM as plug and play without making any changes)

One of the commands we want to send is "RANGE 3;AUTO". And this must be automatically send every time the system starts up.

Our current versions are:

Labview 7.1.1

TestStand 3.0

IVI compliance package 2.2

Those DMM will operate on the same bus, with a different address. Or the new DMM will be used for replacement.

Greetings,

C. Wong

Message Edited by CHIW on 08-23-2007 01:45 AM

[Dennis_Knutson]

You are going to have to change something in order to send the command. In TestStand, you could do a query of the instrument and find out the model number. With a precondition, you could then send the command you want. If you are using the LabVIEW class drivers buried someplace in a step, you could do something similar with a case statement. If you have LabWindows/CVI, you could modify the IVI driver for the instrument.

IVI is not perfect. The longer you use it, you'll see that you often have to make small changes when changing instruments.