Darrell HarmonSep 27, 2025

Rohde&Schwarz NRP-Zxx USB power sensors are not USB TMC but something undocumented and cursed.

You send it null terminated SCPI commands chunked into 16 byte pieces and 0 padded as USB bulk.

It sends back 16 byte USB bulk, byte 0 indicates what it is which can be a status, a little endian single precision float, 10 bytes of string or an indication that it's done sending a string.

Show threadAndrew ZonenbergSep 27, 2025

@dlharmon That's definitely cursed.

Are all of the NRPs like this?

Show threadDarrell HarmonSep 27, 2025
@azonenberg The newer ones are USB TMC.
Show threadAndrew Zonenberg
@dlharmon ah good to know I've been thinking of buying a NRP18T or something in that range. So that's regular TMC?
Sep 27, 2025 at 4:59pmWeb
Show threadDarrell HarmonSep 27, 2025
@azonenberg Yes, new ones have USBTMC. The old family are all NRP-Zxx. You should be good as long as there's no Z in the model number.