Interfacing pm100 thorlabs power meter with NI-VISA through usb-serial

[CatherineH]

I am trying to interface to the PM100 thorlabs power meter (not the current generation, but an obsolete model) with a computer via a serial-to-usb interface. When I send the *IDN? command to COM3 (USB Serial Port) in the VISA interactive control, the return status is "xBFFF0015". I have the serial port settings the same as the output of the power meter  (2400 Baud, 8 data bits, 1 stop bit, no parity).

[Dennis_Knutson]

You could have the wrong type of serial cable, sent the wrong command, sent the wrong terminator, sent no terminator.

[nyc_(is_out_of_here)]

Take the USB-serial cable out of the equation, and use a computer with a real serial port, and use Hyperterminal to communicate with the device.

That will tell you alot about the termination required and everything else.

[CatherineH]

I unplugged the USB serial cord from a USB hub at the front of my computer and plugged it in the back, and now it works. I don't really understand why :s 😛