rs232 maximum cable length

[Ab4bakar]

how can one increase the maximum length of RS-232 from 50ft  to 300 ft

[nyc_(is_out_of_here)]

use RS232 to Ethernet converter boxes at both ends

http://www.blackbox.com/Store/Detail.aspx/CAT5-DB9-Line-Driver/ME890A

[AnalogKid2DigitalMan]

Could also go for the short-haul modem route:

http://www.blackbox.com/Store/Detail.aspx/Short-Haul-Modem-8211-B-Async-SHM-8211-B-Async-4-Wire-Stan...#

Achievable length using traditional RS-232 depends highly on cable capicitance (the lower the better), twisted pairs, shielding, and desired baud rate (you have to go slower the farther you go). The farthest I have has to go yest was 50', used high qulity cable, 19.2K was not problem.

-AK2DM

[Henrik_Volkers]

I once did about 150m two pairs unshielded twisted telcom cable with 9.6k , but it was old equipment with strong drivers, nowadays you can be happy to get 9V 😉

For longer distance (in the 'old days' ) the single ended voltage driven RS232 was converted to differential signals (RS422,RS485..) or current loop (TTY), today you use Ethernet or wireless 😉