7Pure Cable Replacement Mode

7.1 Data Cable

The module has the capability of being preset into a pure 5-wire data cable replacement mode. The 5 wires being RX, TX, CTS, RTS and GND. This mode requires no changes to a host application since the Bluetooth connection is automatically set up on power up and will retry when the connection drops.

By implication, two devices are needed to replace a cable. One device is pre-configured to always be a master and the other, a slave.

Assuming the Bluetooth address of the master to be <bdaddr_m> and that of the slave to be <bdaddr_s>, the master module is configured by sending it the following AT commands.

AT&FATS512=1ATS504=1ATS507=2ATS530=2000AT&WAT+BTR<bdaddr_s>

Where the ATS507=2 setting puts the device in DSR drop mode only. This means that when the device needs to be reconfigured, deasserting the DSR line will ensure that the module responds quickly to AT commands. This further means that in stand alone mode, the DSR input line MUST be asserted e.g. 0v in TTL signal mode.

The slave is configured by,

AT&F

ATS512=4ATS0=-1

AT&W

AT+BTR<bdaddr_m>

27 of 36