serial interface cable
9 pin D-SUB female connector
14 pin Ricoshet SE connector
The Metricom Ricochet SE was a wireless packet modem operating on the 902–928 MHz licence-free ISM band at 100 kbps RF data rate, introduced as the third generation of Metricom’s Ricochet family. It connected to a host PC via an RS-232 serial cable conforming to ANSI/TIA/EIA-232-F (1997), the revision of the standard originally introduced in 1962. The modem is AT-compatible, using the standard Hayes command set, and supports optional link encryption — a feature absent from the earlier Phase I variant. The PC end uses a DE-9 female connector (DTE); the modem end terminates in a proprietary 14-pin connector carrying the standard RS-232 handshaking signals on pins 1–9, with modem-specific lines on pins 10–14 including SEREN on pin 14.
Notes
The cable is straight-through for all RS-232 signals between the DE-9 (PC side) and the 14-pin proprietary connector (modem side). DE-9 pin assignments follow the TIA/EIA-232-F DTE standard: pin 1 DCD, pin 2 RD, pin 3 TD, pin 4 DTR, pin 5 GND, pin 6 DSR, pin 7 RTS, pin 8 CTS, pin 9 RI. The Ricochet SE and Phase II (original) modems both support link encryption; the Phase I modem does not. The same Ricochet modem hardware is used with PC or Macintosh connections, differing only in the cable supplied.
References
- Ricochet Modem Reference Guide — Metricom, Inc., 1997
- Low-Voltage, Single-Supply 232-Standard Interface Solutions (SLLA083A) — Texas Instruments