9 pin D-SUB female connector at the cable
4 pin Magellan special connector at the GPS
The Magellan GPS 315 (and its sibling, the GPS 320) are late-1990s handheld consumer GPS receivers that connect to a PC via a proprietary interface cable. The PC end of the cable terminates in a standard 9-pin DB9 female connector; the GPS end uses a proprietary 4-pin Magellan-specific connector for which no manufacturer pinout has been publicly released. The unit outputs NMEA 0183 data (versions 1.5 and 2.1) over a de facto RS-232 path at a default rate of 4800 baud, selectable to 1200, 9600, or 19200 baud, with 8 data bits, no parity, and 1 stop bit.
| Name | Pin | Pin | Name |
|---|---|---|---|
| +V | 1 | - | NOT 12V |
| -V | 3 | 5 | Signal Groung |
| TD - Transmit Data | 2 | 3 | Transmit Data |
| Receive Data | 4 | 2 | Receive Data |
Signals
The left-hand columns describe the proprietary 4-pin Magellan GPS-side connector; the right-hand columns describe the DB9 female PC-side connector.
GPS-side (proprietary 4-pin Magellan connector)
- +V — External power positive; accepts 9–18 VDC via the power/data cable (cable wire: Red)
- -V — Power ground (cable wire: Black)
- TD – Transmit Data — Serial data transmitted from GPS to PC (cable wire: Orange)
- Receive Data — Serial data received by GPS from PC (cable wire: Yellow)
PC-side (DB9 female)
- Pin 2 – Receive Data — Receives serial data from GPS (DB9 pin 2)
- Pin 3 – Transmit Data — Transmits serial data to GPS (DB9 pin 3)
- Pin 5 – Signal Ground — Signal ground reference
Notes
The DB9 female connector at the cable PC end is wired straight through; Pin 2 carries data out from the GPS, Pin 3 carries data in to the GPS, and Pin 5 is signal ground. The cable also supplies external power (9–18 VDC) to the GPS unit via Red (+V) and Black (GND) wires; this is not RS-232 signalling voltage.
To connect an external device such as a Magellan DBR-2 or DBR-3 via the PC cable, a null-modem adapter (e.g. Radio Shack P/N 26-264A) and a gender changer (P/N 26-280A) are required, because the GPS-side pinout is the reverse of a standard PC DB9 arrangement.
Available cable accessories include: PC Interface Cable with Cigarette Lighter Adapter; Power/Data Cable (bare wires); Data Cable; and External Power Cable with CLA.
The NMEA 0183 output supports sentence sets for versions 1.5 (APA/XTE) and 2.1 (GSA). Checksum output is off by default.
The proprietary 4-pin GPS-side connector is a Magellan-specific part; Magellan (Thales Navigation) did not publish a public specification for its pinout.