Code name 4IG means 4 channel current module with galvanic insulation between channels (and system too). It has internal power supply 24V / 20 mA for current loop sensors (easy to install).
Each channel has 3 terminals – 24V, input and ground. This makes it easy to connect both active and passive sensors.
Communication and power inputs use a 10 pin connector (flat cable) on the bottom of the enclosure.
We were thinking about using several communication protocols and finally decided to use the well known (but not the best) MODBUS RTU protocol.
Every bus oriented connection (as is the case of RS485) requires every connected device to have it’s unique address. A 4-position DIP switch on the bottom of the front side can be used to assign one.
The DIP switch is low profile, right angle. But easily accessed. MODBUS RTU accepts address range from 1 to 250, so value 0 on the switch assigns address 16.
The module has 2 system LEDs (module state and RS485 communication signalization) just above the DIP switch and one LED for each channel.