topic Re: Output a boolean bit on gpib using VISA in LabVIEW

Output a boolean bit on gpib using VISA

Alex_Aust — Mon, 19 Jun 2006 23:57:32 GMT

The program that is being developed is to test a California Instruments power supply model 801RP.

The problem is with the function that switches the output of the power supply on and off, the command is "outp <boolean>".

The question I am raising, how can I send this command with a visa transfer over a gpib interface?

Re: Output a boolean bit on gpib using VISA

RayFarmer — Tue, 20 Jun 2006 11:08:09 GMT

Hi Alex,

How does the instrument maunal define <boolean>?

Usually its "outp 0 | 1 | OFF | ON"

If it responses to 0 or 1 then you can convert your boolean to numeric 0 for False and 1 for True.

Regards

Ray Farmer

Re: Output a boolean bit on gpib using VISA

Alex_Aust — Tue, 20 Jun 2006 22:10:57 GMT

Ray

The Boolean is a '1' for on or a '0' for off.

Using a normal "visa write" which is a alpha numeric transfer I have been unable to find a way to just transfer the boolean. The equipment responds with a command failure.

I have tried transfer as a binary pattern in the high level of visa transfers but labview returns a not allowed in this session.

Thanks for your reply

Alec

Re: Output a boolean bit on gpib using VISA

Dennis_Knutson — Wed, 21 Jun 2006 03:09:00 GMT

Why would you try to output just the Boolean when the command is "outp ". Why don't you try writing "outp 1" or "outp 0"? If you have an electonic copy of the programming manual or can provide a link to one, it would help if the above commands do not work.

Message Edited by Dennis Knutson on 06-20-2006 09:10 PM

Re: Output a boolean bit on gpib using VISA

RayFarmer — Wed, 21 Jun 2006 06:03:38 GMT

Hi,

Its as Dennis says,

Just send the string "outp 0" to set the output off and "outp 1" to set the output on.

If you have a boolean control, wire this to the boolean to numeric converter then use one of the string functions to concat or format the string with "outp ".

In fact there is a string function that provides a string output based on a boolean input.

Regards

Ray Farmer