PLC programming Languages

What are the PLC programming languages?

There are five languages according to IEC-International Electrotechnical Commission, Section 61131–3
they are,

1. Ladder Diagram (LD)
2. Sequential Function Charts (SFC)
3. Function Block Diagram (FBD)
4. Structured Text (ST)
5. Instruction List (IL)

A.Ladder Diagram

1. Ladder diagram is similar to Relay logic system which actually collective response of switches and mechanical relays.
2. These physical control devise are replaced by program logics in ladder diagram mostly (there must be control relays need to be attached with PLC,but its number can be significantly reduce while implementing PLC compared to previous relay logic technology )

• the name Ladder Diagram came from as it looks like ladder with two vertical rails, and the horizontal RUNGS
• Each rung similar to a relay logic schematic, which represent the electrical connections
• Left hand side of the Rungs are the Input side and right-hand side represents outputs or the logical conditions

Advantages of Ladder Diagram

• Easy to follow similar like electrical schematics, no need for …(Continue reading)