Is COM10 Serial Port accessible using VISA/Serial?

[palley]

The serial port labelled by the system as COM10 seems to be unavailable to my application.

I am using the serial port support in VISA and it fails when I attempt to open COM10 by using the same name mapping rules (-> "ASRLxxx" or whatever) I successfully use for other comm ports in the range COM1-COM14.

Is there something special about 10? If so, how do I access it as a serial port?

Thanks

[drohacek]

ASRL10 maps to the parallel port (LPT1). Check out the NI-VISA help file (Start>>Programs>>National Instruments>>VISA>>NI-VISA Help) for more information. If you search for lpt1, you should find the topic "Serial Port Support". This is the topic that documents that ASRL10 accesses LPT1. It also states that the VISA interface number (e.g. ASRL10) may not equal the COM port number (e.g. COM10).

You probably can just use the COM alias (COM10) instead of ASRL10 to access the serial port at COM10 on your system. The best thing to do is probably to look in National Instruments Measurement and Automation Explorer (MAX) to determine the VISA alias for your serial port at COM10. In MAX, expand My System>>Devices and Interfaces>>Ports (Serial & Parallel) to see how VISA is aliasing your ports.