Typically, you can use the "VISA Configure Serial Port" to select which port talk to which instrument. You can use a "VISA Resource Name" control on the front panel to identify which port is used with a given instrument.
All the communication settings are done with the Configure Serial Port vi. You then send commands to the instrument using communicate with the VISA Write. You can monitor responses by checking the number of bytes at the serial port and diplaying it using a VISA Read and attaching the output string to a display (on the front panel). As for deciding which port to set with which instrument, first cjeck what ports the instruments can talk to. Is it limited to COM1 or COM2? What settings should be used, and so on. Verify that you can satisfy the requirements of the instrument. Fom that you decide what port to attribute to the intrument. Providing an example would require knowing a bit more what you are using for a multiple Serial Port. I would not want to lead you in the wrong direction. Hope this helps.. JLV
