Below is the detailed schematic of the opto-isolated high speed digital inputs. All opto-isolated digital inputs are NPN type.

Schematic:

Schematic of High speed input

Notes:

•The opto-supply (pin 9 of 10 pin I/O connector) must be connected to at least +12VDC, but not exceed +48VDC, in order for the digital inputs to operate at maximum efficiency.  

•When a digital input is pulled to ground, current will flow from the opto-supply to ground, and the opto-isolator will then power on and activate the corresponding input(s).

•To deactivate the input, a digital input should be left unconnected or switched back to the opto-supply. This will stop current from flowing through the opto-isolator to ground.

Applies to:

10-PIN DIO connector (High speed Input/Output) Pins 5 to 8

Picture showing location of high speed input/output