Frequently Asked Questions

RS232/RS485/RS422 QUESTIONS

7) HOW COULD THE RS232 DATA LINES COMMUNICATION DISTANCE BE EXTENDED?

Answer: The RS232 standard does not specify a maximum distance, however, cable capacitance limits the maximum cable length for reliable operation to 50 feet (15m). Note, however, that the maximum cable length is highly dependent on the baud rate. A recommended limit for use of RS232 at higher baud rates is only 16 feet (3m). RS422 and RS485 can operate reliably up to 4000 feet (1200 m). RS232 to RS422/RS485 converters can be used to convert RS232 to RS422/RS485 and back to RS232, extending the cabling distance over the RS422/RS485 portion of the link. Alternatively, an RS232 repeater can extend the distance. We recommend the REP-232-3P or REP-232-7P optically isolated RS232 data repeaters (extenders). Either REP-232-3P or REP-232-7P are used in pairs to extend the full-duplex RS232 distance up to 4000 feet (1.2 km). Our data repeaters feature optical isolation circuitry to improve protection for your RS232 equipments from transient surges, ground loops, and remote lightning strikes experienced at either end equipment, or along the interconnection cable.