OK I'm at a point where I'd like to just pay someone to clear everything up for me.
I understood that you had to match your inputs (like sensors etc) to your PLC type. This makes sense because if a sensor is sourcing type (pnp), it means that we connect V+ to the sensor (brown) and Vo to a sinking type plc such that current flows from PS to sensor and down to PLC Gnd or 0V, hence sinking.
Also if the sensor is npn them the v+ goes to the plc first, then the plc sources the current to the sensor which sinks the current to 0V.
In this case the plc is stated as a sink type plc in the documents.
This means the sensor would HAVE to be Sourcing or PNP, but I had to use a sinking Npn sensor. So is the manual WRONG?
I tried asking the manufacturer this and they replied with
which is confusing. So Scott comes in and fixes the pnp wiring which is wrong because it was wired for 48V. But then his pnp wiring in Post 71 is exactly the same as what the manufacturer sent for npn which I posted in 70.
Then post 74 confuses me completely because I think Scott is saying that's how to wire an npn input to an npn plc (which is not supposed to be possible) and the diagram shows current flow in different directions in the same wire. Then in Post 78 Scott adds that indeed you cannot connect an npn with an npn!
Throw my slowness to grasp new things into the mix and I'm desperate. So what do I have in the end:
1. A theory that says that I can't connect an npn input to an npn plc.
2. An npn plc that apparently only works with npn inputs! .
3. A wiring diagram from the manufacturer corrected by Scott which seems to show an npn connection and a pnp connection which are identical.
4. And my lingering confusion as to how it all works and a plc that apparently has a SS terminal that must be jumped to 24V in order to work, instead of being able to use the plc as either sink or source the way that SS terminal is supposed to make it work.
I understood that you had to match your inputs (like sensors etc) to your PLC type. This makes sense because if a sensor is sourcing type (pnp), it means that we connect V+ to the sensor (brown) and Vo to a sinking type plc such that current flows from PS to sensor and down to PLC Gnd or 0V, hence sinking.
Also if the sensor is npn them the v+ goes to the plc first, then the plc sources the current to the sensor which sinks the current to 0V.
In this case the plc is stated as a sink type plc in the documents.
This means the sensor would HAVE to be Sourcing or PNP, but I had to use a sinking Npn sensor. So is the manual WRONG?
I tried asking the manufacturer this and they replied with
which is confusing. So Scott comes in and fixes the pnp wiring which is wrong because it was wired for 48V. But then his pnp wiring in Post 71 is exactly the same as what the manufacturer sent for npn which I posted in 70.
Then post 74 confuses me completely because I think Scott is saying that's how to wire an npn input to an npn plc (which is not supposed to be possible) and the diagram shows current flow in different directions in the same wire. Then in Post 78 Scott adds that indeed you cannot connect an npn with an npn!
Throw my slowness to grasp new things into the mix and I'm desperate. So what do I have in the end:
1. A theory that says that I can't connect an npn input to an npn plc.
2. An npn plc that apparently only works with npn inputs! .
3. A wiring diagram from the manufacturer corrected by Scott which seems to show an npn connection and a pnp connection which are identical.
4. And my lingering confusion as to how it all works and a plc that apparently has a SS terminal that must be jumped to 24V in order to work, instead of being able to use the plc as either sink or source the way that SS terminal is supposed to make it work.