URM37 V5.0

I have bought 10 pieces of URM37 V5.0.
These are by default serial-TTL.
After power on led blinking 1-long 1-short and then stays off permanently.
The sensor is out of order.
Can someone help me get the sensor to work properly?
I have bought 10 pieces of URM37 V5.0.
These are by default serial-TTL.
After power on led blinking 1-long 1-short and then stays off permanently.
The sensor is out of order.
Can someone help me get the sensor to work properly?