The device can operate independently or can be connected to a master device with a Modbus RTU protocol.

Water level is measured by a system of three float switches, or by a linear pressure switch sensor. The measurement method is configurable. For device configuration or/and for communication with the superior system,  the MODBUS RTU protocol is used.

The module is powered by 12-24V DC.

Inputs:

4-20mA or 0-10V ...for connection of level sensor (via this interface the sensor can be supplied with 12V, 15V or 24V DC, max. 1W)

Contact input No.1 ... signaling of upper error level - by float switch

Contact input No.2 ... signaling of working level - by float switch

Contact input No.3 ... signaling of low water level - by float switch

4 x measurement input ... measuring current through connected pump (using external current transformer)

Power supply 230V AC ... powering built-in solid state switches

Outputs:

4 x solid state switch ... optically isolated triac switches

Switching power by triacs is 200W via one output (total 700W).
Pumps can be connected:
- up to 200W directly to the module output,
- over 200W via a three-phase contactor with motor starter