Help with NAT9914 Programming

[RickD]

I am programming a device that will act as a listner only, with the NAT9914 and a PIC microcontroller. I am having trouble interpreting the reference manual and other documents. My main questions are does the 9914 take care of the required IEEE 488.2 commands and if so, how does it know what to respond for *IDN? and others requiring device specific information. Also if it does not take care of them, I am confused as to how to deal with these commands, the IEEE 488.2 standard specify that most of the required command set needs you to read or write to the Event Status Register, which is not discussed in the NAT9914 reference manual.

Any help would be great, we are pretty confused

Rick

[AaronK]

Hi Rick,
The NAT9914 handles the communication layer, but not interpreting too much of the data, much like an RS232 chip can hand you data, but doesnt know what it means. For the rest of the model, you will either have to create a software construct for it, or consider using NI-Device.

There is a good explanation of what you will have to do (and what NI-Device can do) at http://zone.ni.com/devzone/conceptd.nsf/webmain/193EB9FCC3AA5CAF86256AD30063C1DC?opendocument.

Let me know if you have any questions!

Best Regards,
Aaron K.
Application Engineer
National Instruments

[GPIB_Guru]

There are no hardware chips that I am aware of that handle any command parsing. A parser tends to be the one of the most complicated portions of a non-controller instrument. I recommend looking at syntactic parsers like lex for parsing.

The ESR (Event Status Register) is a software register. As your parser (and other blocks of your device) detects problems, it must set bits in the ESR.