What is the maximum cable length for serial RS-232 transmission?

RBR supplies RS-232 extension cables up to 50m. See RBR cable guide for the available options.

Beyond 50m, RS-232 is a generic protocol, so the practical limit depends on the quality of the cable and the baud rate rather than on the instrument. We have run past 200m at 9600 baud with good cable. Longer runs are at your own risk: RBR neither supplies nor tests the cable for them.