Basic PLC Program

Input signal from Input device will entrance to PLC by Input module. After that PLC will process Input signal with Processor memory. Then PLC will transfer Output signal to Output device by Output module.

Basic componant of PLC Programs .

1. CPU ( Central Processor Module )
Process software application in ROM/RAM. Some application depend on Brand or Type.

2. Memory Unit
- ROM : Storage functions of the PLC Programs, Have battery to back up.
- RAM : Can be divided into EPROM, which will require special equipment to write and delete
3. I/O Unit
- Digital input module : Receive digital signal from Input device. ( 24VDC/VAC, 110V, 220V )
- Digital output module : Send digital signal to Output device. ( 24VDC/VAC, 110V, 220V )
- Analog input modle : Receive analog signal from Input device. ( 0-10VDC, 4-20Ma )
- Analog output module : Send analog signal to Output device. ( 0-10VDC, 4-20Ma )

4. Power supply
To supply electricity to PLC Program device.

5. Base module
To connect all PLC Programs device.