The comms connector is a standard DB9. It provides an RS232 compatible interface, and is used for communications with a PC for programming and use with SPLatLink.
The RS232 interface is a basic interface with transmit data, receive data and ground. Pinouts are as follows:
| Pin | Signal name | Comments |
|---|---|---|
| 1 | ||
| 2 | RxD | Serial data output from board |
| 3 | TxD | Serial data input to board |
| 4 | DTR | Permanent +5V via 2.2K (output) |
| 5 | Gnd | 0V, signal ground |
| 6 | ||
| 7 | RTS | Request to Send signal out of board |
| 8 | ||
| 9 |
The interface has a special design that allows several boards' interfaces to be connected in parallel, like pin to like pin. This makes possible small systems of up to 5 boards in a multi-drop communications configuration, connected perhaps to a shared modem. Please contact SPLat Controls for information about suitable Firmware to support this arrangement.
See also RS232 pinouts: A primer