Newport 841-P-USB (Black case) Notes

I picked up an old USB optical power meter on eBay. This meter is on longer supported by Newport, and they don’t list it on their main site. If you go to their download site ( you can find software for the 841-P-USB, but as far as I can tell this is for a newer version of the instrument. The device does not appear to work with PMManager or any of the other software Newport currently support.

It looks like there were two versions of the 841-P-USB, and earlier “black case” version and a newer silver case version. The silver case version seems to have an expanded command set, and possibly runs at a faster baud rate.

However, you can talk to the 841-P-USB over serial and get data out of it. You should use 57600 baud (8N1). The 841-P-USB manual (for the silver version, which you can find on the site above) lists several commands. I used the following to take measurements:

*SOUZero offset
*CVUTake single measurement
*CAUPrint continuous measurements
*CSUStop continuous measurements
*F01Show device and sensor information
*PWC00000Set the wavelength used for connection (e.g. *PWC00532)

If I do find any software that works with this instrument, or further information about the device. I’ll update this blog post.