Omron PLC Center

Let’s see how the input circuits of a contract plc. This will give us a better understanding of how we should bind. Bad things can happen when we get them wrong wire?

Typically, DC-input modules are available that can work with 5, 12, 24 and 48 volts. Make sure you buy what your needs the input devices that you will use it.

We’ll first see how the DC input of labor. The DC input modules allow us to get in touch is PNP (sourcing) or NPN (sinking) transistor-like devices to them. If you use a normal toggle switch (or push button, etc.), generally do not care if you wire as NPN or PNP. We must note that most of the PLC will not let us mix NPN and PNP devices on the module itself when using a sensor (photo-eye, prox, etc) that we do, but must be on their output care-configuration. Always check whether it is PNP or NPN. (Check with the manufacturer if it is safe)

The difference between the two is whether the load (in our case, the PLC is the load), activated from the ground or positive voltage. NPN has a sensor on the load on the ground, while a PNP device is switched on the load on the positive voltage.

diagram below is what lower than the output NPN and PNP sensors seem.

NPN on the sensor we connect one output to PLC input and output of the other ground feeding. If the sensor is operated by the treatment itself plc, together, we conclude for two reasons. NTC sensors are used most frequently in North America.

Many engineers say that PNP is better (ie safer) because the burden is passed on to the floor, but what is best for you. Remember, the planning for the worst.

PNP on the sensor, we connect a positive voltage output and the output of others for the PLC input. If the sensor is operated by the treatment itself plc, we should come together to both V + ’s together. PNP sensors are commonly used in Europe.

Within the sensor, the transistor is only as a switch. The sensor circuit within said output transistor on when a goal is to make available, too. Transistor closes the circuit between the 2 upper left. (V + and the PLC input).

The only thing that are accessible to the user terminals labeled COMMON, INPUT 0000, INPUT 0001, INPUTxxxx … The common terminal, or connected to V + or ground. Where connected depends on the type of sensor used. In the case of using an NPN sensor this terminal connected to V +. When using a PNP sensor this terminal is) to 0V (ground.

A common switches (eg limit switch, button, toggle, etc.) would be connected to the inputs in a similar manner. One side of the switch is directly connected to V +. The other end is the input terminal plc. This implies that the common terminal is connected to 0V (mass). If the city is connected to V + then simply connect one end of the transition to 0V (ground) and the other end to input terminal plc.

The optocouplers are used to isolate the PLCs internal circuit from the inputs. Therefore no possibility that an internal electrical noise in the circuit. They work by converting the electrical signal input to the light and then converts the light back into an electrical signal is processed by the internal circuitry.

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