4 opto-isolated inputs (No ground reference), configurable as current sink or current source in groups of 2 with 1K current limit resistor.

Digital 

COM  Connect to ISO+ for SINKING input. Connect to ISO- for SOURCING input. 

DI1,DI2 share a COM input.  DI3,DI4 share a COM input.


DI1-4 – 

If COM is set to SINKING connect ISO- to activate input.


If COM is set to SOURCING connect ISO+ to activate input.


ISO+ and ISO- are supplied for easy connection but any power connection can be used.  Ensure the input signal and the COM connection share a common ground reference.