Inputs - Yes : Outputs - No
This PLC can't physically control anything directly. Via comms it could, but in that case the PLC does not have total control, because the external device can override this controller. I have seen many successful projects where a PLC is employed to mimic/monitor a real-world application, and its only outputs are not physical outputs, just alarms or status data.
Inputs - No : Outputs - Yes
This PLC hasn't got a clue what is happening in the real world, so could be blindingly stacking pallets 345 high when then the maximum is 3. I have seen many successful projects where a PLC has no feedbacks, but blindly carries on changing its outputs. We have all seen such applications, and they are very common, traffic lights (without road or other sensors) is just one example.
There is no right answer to the OP's question - a PLC can be deployed in many scenarios - to state that inputs or outputs are more important is a nonsense,,,,
This PLC can't physically control anything directly. Via comms it could, but in that case the PLC does not have total control, because the external device can override this controller. I have seen many successful projects where a PLC is employed to mimic/monitor a real-world application, and its only outputs are not physical outputs, just alarms or status data.
Inputs - No : Outputs - Yes
This PLC hasn't got a clue what is happening in the real world, so could be blindingly stacking pallets 345 high when then the maximum is 3. I have seen many successful projects where a PLC has no feedbacks, but blindly carries on changing its outputs. We have all seen such applications, and they are very common, traffic lights (without road or other sensors) is just one example.
There is no right answer to the OP's question - a PLC can be deployed in many scenarios - to state that inputs or outputs are more important is a nonsense,,,,