USB GPIB Errors

[Rich_Martin]

I am trying to use a Measurement Computing USB-GPIB interface to control an HP4192A Impedance analyzer. My problem is getting a VI to work with the instrument. Whenever I try to use either simple GPIB open and read commands, the system locks up (Win2000). If I try to use a VISA read, I get an error -1073807312.

I have checked the functioning of the device using measurement computing's interface software (GPIB Keyboard) as well as NI's Visa Interactive Control. Using either of these programs I can send instructions to the device as well as read data from the device. I have also tried to use the LV7 Instrument I/O Assistant. When I launch the Assistant, It locates the GPIB device as GPIB0::17::INSTR and is able to read and parse one set of data. W
hen I try to use the settings and run the VI, I get the error mentioned previously. I would prefer to use the GPIB commands rather than the VISA since I already have the VI written, but at this point I will be happy to read one data point without a crash. Any help in this will be greatly appreciated.

[JoshuaP]

Hey Rich,

National Instruments GPIB driver was not developed to work with 3rd party USB-GPIB devices. Our GPIB driver has been designed to work with our USB-GPIB devices and we can guarantee that it can be integrated with LabVIEW 7.0 and all of our examples and instrument drivers without any problems.

http://sine.ni.com/apps/we/nioc.vp?cid=11190〈=US

http://zone.ni.com/idnet97.nsf/9b2b33e1993d877786256436006ec498/49992e6e9671335d862568ab005fbc3a?OpenDocument

Our GPIB VIs make direct calls to our GPIB driver DLL for National Instruments GPIB devices and they will not work with 3rd party GPIB controllers. Many manufactures make drivers that can be controlled with VISA, however you will have to check with your instrument manufacturer for compatibility
with VISA.

If you are having problems with a 3rd party GPIB device I would recommend you contact the manufacturer of your GPIB device to see if they have a GPIB driver that can be used with LabVIEW and VISA.

I hope this helps out.

JoshuaP
National Instruments

[GPIB_Guru]

The error you are getting, BFFF0030 (converted to HEX), is indicative of an abort. LabVIEW may be using asynchronous I/O and timing out, so it is aborting the operation, which would really indicate that your error is a timeout.

If you are getting a timeout, it may be because the GPIB-USB converter does not play nicely with the USB bus and doing things slowly (e.g., I/O assistant, interactive control, ...) it works correctly. If you do things too quickly (e.g., using a program), it may fail. If this is the case, the only way you will be able to properly use this controller is if you add manual delays to your application. Have you tried this? In LabVIEW, wire the open, write, and read together, but place a delay VI in between to see if this helps. If it does, i
t is probably something you will have to do with this interface. I have used an NI board without any problems, but I do not have experience with the MC board to ascertain if this is a common occurrence.