serial interface cable
9 pin D-SUB male connector
8 pin RJ45 (8P8C) male connector
The Phase II PC modem cable connects a PC’s DE-9 (9-pin D-sub) serial port to the Metricom Ricochet Phase II wireless packet modem using an RJ-45 8P8C plug. The Ricochet modem operated on the 902–928 MHz licence-free ISM band at 100 kbps RF data rate and presented a Hayes-compatible AT command interface to the host over RS-232. The Phase II generation supports encryption, distinguishing it from the earlier Phase I variant. Standard RS-232 signals — including RXD, TXD, DTR, DSR, RTS, CTS, DCD, and RI — are carried across the cable with the DE-9 DTE pin assignments defined by TIA/EIA-232-F.
Notes
- The DE-9 end connects to the PC serial port (DTE); the RJ-45 end connects to the Ricochet Phase II modem (DCE).
- The Phase II modem supports encryption; the Phase I modem variant does not.
- The Ricochet modem family is AT-compatible and responds to standard Hayes commands (e.g. ATZ, AT&C, AT&D).
- Do not confuse this cable with the Phase I variant, which uses a different RJ-45 signal assignment.
References
- Ricochet Modem Reference Guide — Metricom, Inc., 1997
- Low-Voltage, Single-Supply 232-Standard Interface Solutions (SLLA083A) — Texas Instruments