Quatech Bluetooth To Serial Converter SS-BLT-400 - Manual (Page 10)

9
LED Indicators
SYS (Red)
：
It is the power indicator, when the power is on then the LED will blink once
per second.
Pair (Green)
：
Before connecting to synchronize between the device and the “BT RS232
Config Tool” software, the green LED will be blinking
After connecting to synchronize between the device and the “BT RS232
Config Tool” software, the green LED (Pair) will be on
RX (Red)
：
Data received indicator (When data are received from the network, the LED
will be on.)
TX (Green)
：
Data sent indicator (When data are sent out to the network, the LED will be
on.)