IOGear GBS301 - Manual (Page 12)

Operation
10
DIP Switch 4 is used to set the serial adapter as master or slave:
Master mode: Switch 4 ON
Slave mode: Switch 4 OFF
Master Mode
If you are interconnecting two IOGEAR Bluetooth adapters, you must set one of them
to master and the other to slave.
Slave Mode
Please note that Bluetooth software applications (like Widcomm) will only be able to
discover and connect to slave devices.
Therefore, if you are connecting this unit to a serial device to be accessed by a
Bluetooth-enabled PC/PDA at the other end, make sure to set the IOGEAR Bluetooth
serial adapter to slave mode
Switch 4