Model 2281

Asynchronous Metallic Isolated Modem

The S.I.Tech Model 2281 is an optically isolated RS422 to RS422 converter. It combines connector to connector compatibility with outstanding performance characteristics. It supports full duplex transmission between compatible EDP equipment at speeds up to 2.5 Mbps.

Features and Specifications

Interface:	Two pair bidirectional RS422 4-wire interface
Connectors:	DCE DB9-P (male), DTE DB9-S (female)
Data Rate:	0 to 2.5 Mbps
Cable:	Shielded 100 - 200 twisted pairs. Using 24AWG with 52.5PF/m shunt capacitance cable length supported of 1200m at rates less than 90kbps and falling to 20m at rate of 2.5Mbps.
Isolation:	1000VAC between the DTE port and the DCE and power ports
Power:	10 to 15VDC or 8 to 13VAC, about 2 watts. (Use S.I.Tech #2121 external power supply)
Temperature:	0 to 50oC

RS - 422 DB-9 CONNECTOR PINS UTILIZED BY 2281 MODEM