Feature:
* With network expansion function.
* With power supply function.
* Connect the controller and the unit. The last unit is connected back to the controller to realize the loop redundancy function.
* When the loop detection is disconnected, the ACTIVE indicator light is on.
* When the loop detection is closed, the ACTIVE indicator light is off.
* Self-checking function. When self-checking internal faults, the ERROR indicator light is on, and it goes out when the fault is restored or there is no fault.
*It can be connected to a power adapter for power supply.