Can I use NI Spy with a GPIB card from Keithley or CEC?
NI Spy is a debugging tool from National Instruments. It is typically installed with LabVIEW or LabWindows/CVI or other software products from National Instruments.
This tool can log the commands sent over the bus to an instrument. Sometimes these commands are not easily apparent, especially when using high level IVI or VXI/PnP instrument drivers. These high level drivers provide function calls that are translated into one or more instrument specific command. A tool such as NI Spy can be very helpful in troubleshooting situations.
When controlling an instrument with a GPIB board from CEC/Keithley, one could be using three different communications API to program the GPIB board:
- the send and enter commands of CEC488 driver (IEEE_32m.dll) to send the instrument's command syntax (SCPI or DDC)
- the ibrd and ibwrt commands of NI compatibility mode (GPIB-32.DLL) to send the instrument's command syntax (SCPI or DDC)
- VISA I/O Layer with suitable passport for CEC/Keithley cards
When using a GPIB card from CEC/Keithley, NI Spy can log data only when making use of the VISA I/O Layer API. Since the ibrd/ibwrt or send/enter commands are used together with the instrument specific commands, the NI Spy utility does not offer much more information. However, the IVI or VXI/PnP drivers always make use of VISA I/O layer. In this case, NI Spy can give insight into how the function calls of the driver are translated into instrument specific commands.
This FAQ Applies to:
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FAQ ID 71721View all FAQs »