NI Simulator query question

[ceilingwalker]

Hello. I have an NI Instrument Simulator that I have been testing using the VISA test panel in MAX to test. I am not quite sure what is happening however, when I query a simple *IDN?, it will read 00062\r\n". Then when I query it again, it reads "National\sInstruments\sGPIB\sand\sSerial\sDevice\sSimulator\sRev\sB.1\n". When I query it again, it reads the "00062\r\n" again. It flip-flops between the two with each query. Does this me that I will need to continually query twice, to get the desired data read? I am not sure how to put this in a Vi. I have tried a lot of different things but it always come out the same. Even if I clear the register and tried an individual write then read, it does the same thing. Is this to be expected, and how do I do this within a Vi?

Thanks much for your support.

[Dennis_Knutson]

Either do two consecutive reads or disable the termination character and do a single read with the VISA Bytes at Serial Port to determine how many bytes to read.

I have no idea why the ancient simulator is sending two lines of data. An actual instrument will not do that. As long as you are just pretending to have an instrument, it probably does not matter that much. You could even skip the *IDN? query.

[mikeporter]

To expand on Sir Dennis's answer. A real.instrument will document in the manual the information that is returned. Typically, in addition to manufacturer and model number you will get version numbers for the firmware and sometimes the hardware too.

Mike...

[Dennis_Knutson]

Also note that you could have gotten a real instrument for the price of the simulator. A real instrument could be used to acquire actual signals and would be of use outside the classroom.

[ceilingwalker]

It was just that it was coming out of my pocket and the simulator was $35. Also, I needed something compact that could travel back and forth with me. Thank you

[mikeporter]

I see your point, but here in Houston they have a VERY cool place called EPO. You could get an old voltmeter or something with a gpib interface for about that -- who cares if it hasn't been calibrated since some time during the Nixon administration.

Mike...

[ceilingwalker]

Could you give an example please? I looked around Ebay and found nothing except actual test instruments that were incredibly pricey. Thank you

[Dennis_Knutson · Accepted solution]

You need to refine your Google-fu skills. I was thinking of something like this - http://www.amazon.com/TekPower-TP4000ZC-RS232-Interaced-Ranging-Multimeter/dp/B000OPDFLM/ref=cm_cr_p...

[ceilingwalker]

Thank you

[ceilingwalker]

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@Dennis_Knutson wrote:
You need to refine your Google-fu skills. I was thinking of something like this - http://www.amazon.com/TekPower-TP4000ZC-RS232-Interaced-Ranging-Multimeter/dp/B000OPDFLM/ref=cm_cr_p...

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I purchased it but am having trouble getting NI MAX to read from it.