MATLAB: Do I get an error when creating a GPIB interface object for an NI-GPIB card connected to an Agilent USB-GPIB adapter using the Instrument Control Toolbox 2.6 (R2008a)

Question

I connect an NI-GPIB card using an Agilent USB-GPIB adapter to the GPIB interface of my PC. When I try to detect the NI device using the INSTRHWINFO command from the Instrument Control Toolbox, I do not see the device. Further, when I try to create the interface object using the GPIB command, I receive the following error:

 ??? Error using ==> gpib.gpib at 152
 Unable to load NI GPIB interface. Please check the necessary drivers are installed on your machine.

Answer 1

This is an expected behavior when interfacing a NI-GPIB card using an Agilent USB-GPIB adapter and creating an interface object in Instrument Control Toolbox 2.6 (R2008a).

The reason for this behavior is as follows:

The Agilent USB-GPIB adapter shadows the National Instruments (NI) drivers with its corresponding drivers for the GPIB card. In order to prevent the Agilent drivers from overriding NI drivers, do the following:

1. Go to the Agilent Connection Expert software which comes with the Agilent I/O Libraries Suite.

2. Click Tools

3. Click Options

4. Select Agilent 488 options and make sure that the box for Enable Agilent GPIB cards for 488 programs is unchecked.