Open a general air switch, this is the whole cabinet put oneself in another's position of power control, is each cabinet must be some things.
PLC to choose according to the need of engineering.
If the project is small, can be directly with an integration of PLC;
If the project is large, may need module, card type, also may be redundant (
Two sets of used interchangeably)
24 VDC power supply 24 VDC switching power supply, a most PLC is bringing 24 VDC power supply, need according to actual condition to decide whether to the switching power supply.
General PLC relay can be directly to the instruction to control circuit, but also may first by relay relay.
If you charged PLC output is 24 VDC, but a picture of your control circuit diagram of PLC is needed for the node is 220 vac, so you must add a relay, PLC output when the instruction relay action, let from relay control circuit of node normally open or normally closed point.
This is also choose whether to use relay according to situation.
This certainly is an essential part of every cabinet terminal, according to the number of signals can be configured.
If only a simple PLC control cabinet, basic is the need to these items, if you are in control cabinet also need to have other devices, it depends.
For example, you may have to instrument or present at the scene of some small power control box, you may have to increase air quantity.
Or do you want to receive first place machine, PLC might need to increase the switch, etc.
As the case may be.