Optocoupled GPIO are electrically isolated from the rest of the system and require external reference through the COMMON_IN and COMMON_OUT wires.
The termination of COMMON_IN and COMMON_OUT to an external voltage or ground determines if the input or output is Sinking type or Sourcing type.
In output mode, the GPIO performs similarly to switches connecting the GPIO pin to COMMON_OUT. When disabled, the GPIO pin is disconnected from COMMON_OUT and allowed to float. As a result, optocoupled outputs turn on quickly, while the turn-off time depends on how quickly the connected load dissipates the charge
Optocoupled inputs are enabled when voltage is applied across the GPIO pin and COMMON_IN.
Optocoupled GPIO can operate non-isolated by terminating COMMON_IN and COMMON_OUT to the DC_IN or GND wires that power the device.
Connection References
Wire
Termination
Configuration
COMMON_IN
GND
Sinking Input (PNP)
COMMON_IN
DC_IN
Sourcing Input (NPN)
COMMON_OUT
GND
Sinking Output (NPN)
COMMON_OUT
DC_IN
Sourcing Output (PNP)
While it is possible to configure inputs and outputs of the same type, this is not recommended as inputs and outputs must be of opposite type to be compatible. All optocoupled GPIO share the COMMON_IN for input mode and COMMON_OUT for output mode. Therefore, all inputs must be of the same type and all outputs must be of the same type. For example, it is not possible to simultaneously configure sinking output on GPIO0 and sourcing output on GPIO1.
In practice, sinking inputs paired with sourcing outputs is common. This combination is compatible with widely available digital industrial GPIO, which typically only support sinking-type inputs.
Refer to the documentation of the connected auxiliary equipment to ensure a compatible configuration, and remember to leave unused GPIO in a disabled state.
Optocoupled outputs are individually fused to protect against damage from short circuits or overload events. Since no power is consumed from the vision system, optocoupled GPIO have no impact on power budgeting.
