OK so instead of this:

PLC ---------PLC
0V ------------S/S
24V-----------X0

This:
PLC ---------PLC
0V ------------X0
24V-----------sensor +

 

The output of the sensor goes to X0.
24v to S/S.
The other + & - connections of the sensor go to the DC+ and 0v
Max.

 

Yes well that's what I did yesterday and that's how that other sensor stopped working. Post 43.

 

OK I got it working. It's like you said, with the only difference is that I disconnected the com0 to 0v that I had, and with the fact that this is an npn sensor.

Here is the image:


So assuming it's actually because this is an npn sensor instead of pnp sensor, what would be the way to connect a pnp sensor to this plc?

 

If you have it set for a sinking input which it appears you do.
Then normally you use a sourcing sensor, which a PNP is.
Max.

 

If you have it set for a sinking input which it appears you do.
Then normally you use a sourcing sensor, which a PNP is.
Max.

The way I have it set up in this last picture works with the NPN sensor. This same set up does not work with the PNP sensor.

 

That unit must be totally different from a standard Mitsubishi of the same type.
So you will have to use sinking sensors it seems, which a NPN is.
Max.

 

What's weird is that the manufacturer said this was an npn type plc which means that it should use pnp input devices, right? At least that's what I've heard in videos, that you want to match npn devices to pnp plcs and vice versa.

 

Puzzles me why a manuf. would attempt to copy the Mitsubishi, down to the Sink or Source input (S/S) and restrict it to only one configuration?
Max.

 

She just answered this:

Mitsubishi is possible to connect sink with sink/source. But our PLC is sink to connect sink sensor

And she put these pictures up:

 

The Chinese Char shown as : This kind of connection needs two independent power supplies, the sensor needs an independent power supply, and the input of power quite strange, because it shown that Up -24V and Down +24V, that is 48V, and the Positive pin connected to -24V, Gnd connected to +24V, the Power wiring should be the same as the NPN type, the sensor just send the feedback as Source is +24V or Sink is 0V, the PLC side just input +24V or 0V.

 

What if like to know is the following: According to what I've read, a sinking (npn) input must connect to a sourcing (pnp) plc, and a sourcing input must connect to a sinking plc; all of this in order for the circuits to work. Although I'm just starting to get comfortable with s/s concept in theory, I can understand why that is true. If a sensor is sinking, it needs the power from the sourcing plc so that the sensor can sink it, and vv.

So what I wish to clear up is, why if my sensor (the one that worked) is npn (sinking), did it work with a npn sink type plc? According to the manual it's a sink type plc:

 

I have become used to the fact the hard way that not all Chinese instructions are clear or even correct, they consistently issue very confusing instruction details, not at all always correct, not sure if it is always ignorance of the subject or a language problem!.
Max.

 

and a sourcing input must connect to a sinking plc;

That's what I uploaded that the PNP(I guessed) sensor providing the current source to a PLC sink input.

If a sensor is sinking, it needs the power from the sourcing plc so that the sensor can sink it,

That's the second circuit in your posted #70.

So what I wish to clear up is, why if my sensor (the one that worked) is npn (sinking), did it work with a npn sink type plc? According to the manual it's a sink type plc:

The two NPN type shown below, you can see the current direction(arrow) and the blue line.



About the Diagram 6, the external should be connects to a contacts of relay to GND or connects to a C of NPN bjt, and C connects to GND.

 

I have become used to the fact the hard way that not all Chinese instructions are clear or even correct, they consistently issue very confusing instruction details, not at all always correct, not sure if it is always ignorance of the subject or a language problem!.
Max.

It is not a language problem, that was a technical issue, as you can see my posted #71 already mention that, I had try other brand (world famous but from other country) that had RS-232 communication code error in the user manual and that was in Taiwan.

 

I find it strange they would even include a S/S option but in fact the unit appears it does not have it?
Also the 0v-24vdc input supply is usually internal, on the Mits. it is anyway.
Max.

 

Scott

In that diagram you have current flowing in 2 different directions; from the Blue wire to X0 and at the same time from the blue wire to Vo. How is that possible?

 

Scott

In that diagram you have current flowing in 2 different directions; from the Blue wire to X0 and at the same time from the blue wire to Vo. How is that possible?

I just shown the blue line, but they didn't connected together, It means that you can't connect them together directly for two Sinking type as NPN, the same reason that you can't connect two Sourcing type as PNP.

Edit :
You need to add a Sourcing type (as one stage PNP) from sensor to the PLC.

 

What? If the blue line is not connected then there is no Vo going from the sensor to the plc.

 

If the two souncing type as I drew then they can't connected together, It told you that just don't connect them together directly, if you connect them together then it will no harm, but it also doesn't affect anything, so I suggested to add a Sourcing type (as one stage PNP) from sensor to the PLC.