Z-4AI is used to interface analog inputs (Voltage or current, also with bipolar range) with Modbus system. The modules is able to supply all 4 current loops at the same time, this is very useful for 2-wire sensors because the wiring does not need an external power supply. It s a ModBUS Slave and can be coupled with any ModBUS Master device. A 3-way galvanic isolation among Power supply // input // RS485 circuits assures the integrity of your datas.