User's Manual

7
2.2 LED Indicator
After the device is powered on, the DTU will automatically run continuously
according to the configuration, and complete related operations. During this process,
the device's indicator light will indicate different operating states, as shown in the
following table:
DTU status
Power
Modem
SIM indicator
Status indicator
Power on
On
Spare
Off
Off
Dialing..., no fault.
On
Off
Off
Dialing..., fault.
On
Off
On
Dialing is successful, and
connecting center.
On
On
Off
Dialing is successful, but
failed to connect to center.
On
On
On
Connected to the center.
On
Blinking slowly with the same frequency
Short connection to be
activated.
On
Off
Blinking slowly
SIM card is faulty.
On
Blinking slowly
On
In TROY mode.
On
Blinking fast alternatively