Pin Definitions

1. G
2. CTS
3. DTR
4. RXD
5. TXD
6. RST
7. FRM
8. A2
9. A1
10. VCC

Pin 1 - Ground

This is the power and signal ground for the data radio.

Pin 2 - Clear To Send

CTS is a TTL output from the radio which indicates the device's readiness. The radio will drive the signal low to indicate that it can accept serial data. You must stop sending serial data when this signal is driven high or you risk overrunning the buffers and losing data.

Pin 3 - Data Terminal Ready

DTR is a TTL input to the radio which is used to control the device's mode. DTR should be held low during normal operation and only driven high to enter command mode.

Pin 4 - Receive Data

RXD is the TTL-level, asynchronous, serial data output from the radio to the user device. Incoming data (and responses to commands) will be driven on this line. Serial data is formatted in the standard way, with a single low start bit, eight data bits (LSB to MSB), parity (if enabled), and then a high stop bit(s). The baud rate, parity, and stop bit settings are user-configurable.

Pin 5 - Transmit Data

TXD is the TTL-level, asynchronous, serial data input to the radio from the user device. Outgoing data (and commands) should be driven into this line. TXD expects the serial data to be formatted the same was as for RXD (above).

Pin 6 - Reset

Driving RST low will hold the radio in reset. This pin should be left open during normal operation.

Pin 7 - Frame

Frame is held high while data is being returned on RXD.

Pins 8 & 9 - Reserved

These signals are not user-supported and should be left unconnected.

Pin 10 - Power

VCC is the power to the radio. It should be kept between 9V and 28V DC.