I am using GPIB-232CT-A to control Network Analyser with Suse Linux 9.3
and I need to know what I need to start sending the commands using the
serial port.
Unfortunately, the GPIB-232CT-A is not supported on Linux. You can find a list of supported GPIB devices for different Operating Systems here. I would recommend using a PCI-GPIB, or GPIB-USB-B instead. Also, the NI 488.2 driver has not been tested on Suse 9.3, so it's not guaranteed to work; see the driver download page for tested distributions. Thanks.