Hi Suresh,
Thank you for contacting National Instruments. It sounds to me like there are three possible problems.
First, it is possible that there is a configuration problem with VISA. According to Chroma's webpage, this device does use NI-VISA. If this is true, the device should be listed in Measurement and Automation Explorer (MAX) under PXI System when it is properly installed and configured. If this device is not listed in MAX, then we need to make sure VISA is configured to recognize your device. In MAX, select the Tools menu, and select NI-VISA, VISA Options. Select VISA Passports, and make sure there is a checkmark next to "nivipxi.dll - VISA library passport for PXI." Now, select VISA settings and make sure the option to "Show all PXI/PCI Devices
accessible to VISA" is enabled.
Second, it is possible that NI-VISA or the software for your PXI card is corrupt. I suggest you uninstall your PXI device, NI-VISA, and the software for your PXI device. Once your system is clean, I recommend you reinstall NI-VISA, NI-IVI, and the instrument drivers for your PXI device. Once all of the software is installed, then you can reinstall the hardware.
I hope that helps. If that does not solve your problem, I will try to help you as much as I can, but it may be necessary to contact Chroma.
Regards,
David Shatila
Applications Engineer
National Instruments