Marco (Customer) asked a question.
I am going to buy a sinking PLC (1st picture).
I will need to buy a sourcing sensor (PNP sensor, 2nd picture) to use in this PLC.
I will connect 24V to brown wire of the sensor, 0V to the blue wire of the sensor.
I will connect the black wire of the sensor to X1 of the PLC. AND I will connect 24V to C1
Is any of my understanding incorrect??
The Inputs can be sinking or sourcing.
With the sensor shown you would connect:
24 V+ > Brown wire of the sensor
24V - > Blue wire of the sensor & C1 on PLC
Black wire of the sensor >X1 on PLC
See attached pdf from chapter 3 of the Click manual that details sinking/sourcing wiring for inputs and outputs.
I am a little confused here.
=====Sensor======
I copied the 2nd picture from the 2nd page of this pdf, it says that the operation voltage is 10V-30V
https://cdn.automationdirect.com/static/specs/prox12mmam.pdf
Should 'L-' from the 2nd page of the above pdf is 0V or -24V?
====PLC=====
Let go back to the PLC
Should C1 be ground or C1 be -24V?
I asked this because there is 24VDC from the 1st picture. If I connect C1 to be -24V, then the sensor input to the system have total 48VDC of potential difference.
C1 will be your common. In your case that would be the Negative, O VDC line, or negative from the 24VDC power supply. Which is what I meant by 24V -.
SO C1 and L- would be connected to the negative side of your dc power supply.
See the power supply on the diagram of the pdf I attached.
0 VDC = -24VDC it just depends on which side of the tracks you grew up on.
The 24 represents the DC source voltage. While + or - represents which terminal.
Something most of use are familiar with is a car battery. There are 2 terminals Positive and Negative. The terminals could be accurately described as +12VDC and -12VDC.
If you test voltage between the positive terminal (+12VDC) and the negative terminal (-12VDC) you get 12VDC. The + or - on the meter tells you which way electrons are moving through the meter.
Where a lot of people get confused is that they think of an analog signal and a power supply as the same thing. Power supplies want to put out the same constant voltage.
I've been seeing increasing use of the term voltage potential. Seems to have become a buzz word. Probably because more people are playing with circuit boards. Voltage potential is really a misnomer. Voltage = Electrical Potential = Electromotive Force (unless you are feeling extra sciencey). All of which means I get a value X when I measure between A and B.
Even if we had a -10VDC to 10VDC analog signal the max Voltage / Electrical Potential / Electromotive Force would be 10 volts. The signal range would be 20 volts though.
Hope this helps to clarify things for you. If not there is a pretty good chance someone else will say it differently and you'll have that ah ha moment.
Inputs on that one can be sink or source it just depends on which way you wire it. Wire -24VDC (0V) to C1 for Sinking Inputs.
The outputs are sinking. Personally unless there is a REALLY good reason (I've yet to find one) I won't use sinking output.
4 (Black) is the signal wire and is positive on a PNP sensor.
-24VDC on C1 for Sinking Inputs
Happy to help.
I did have one other thing I wanted to mention.
-VDC and 0VDC are used interchangeably.
They are also often called common, but the common doesn't have to be - it could be + . The sinking outputs on that PLC for example would use a + common.
Common really means the side of the circuit that everything shares. Another way to look at it is if I can jump a wire between a bunch of devices on the same side of the circuit and not effect how the circuit functions that side is common.
Ground / Earth / PE are entirely different. While occasionally a design will tie the common to ground I would advise that you don't.
https://accautomation.ca/wiring-3-wire-dc-npn-and-pnp-sensors/
The above post may help you out.
Regards,
Garry
The Inputs can be sinking or sourcing.
With the sensor shown you would connect:
24 V+ > Brown wire of the sensor
24V - > Blue wire of the sensor & C1 on PLC
Black wire of the sensor >X1 on PLC
See attached pdf from chapter 3 of the Click manual that details sinking/sourcing wiring for inputs and outputs.