RS422/485 Application Note
Appendix B: EIA Standard RS-423 Data Transmission

RS-423 (EIA-423) is another standard used in point to point communications. RS-423 data transmission uses an unbalanced line driver that connects to an RS-422 type balanced line receiver as shown in Figure B.1. The RS-423 line driver is unique to this system. It produces voltage similar to RS-232 but has a slew rate control input that is used to limit rise times and cross talk on the data lines. Typical adjustment on the slew rate control is from 1 to 100 µs. This is done by the proper selection of one resistor on the wave shape control input.

Figure B.1 RS-423 Interface Circuit