PLC - Programmable Logic Control | Block Diagram, Input PLC Microprocessor Based Control System Block Diagram. Solenoid valves and other actuators are used to control process variables under program direction. A programmable timer in the system determines the rate at which control loops are serviced. PLC SOLUTIONS: BLOCK DIAGRAM OF PLC A simplified block diagram of a PLC shown in above Fig. It has three major units/sections. I/O (Input/Output) Modules. CPU (Central Processing Units). Programmer/Monitor. The input section converts the field signals supplied by input devices/sensors to logic-level signals that [Explained] PLC Block Diagram | Programmable Logic PLC Block Diagram. You will understand the working principle of PLC from the block diagram of PLC stands for Programmable Logic Controllerdays, PLC becomes more and more popular in industries for automation purpose.5/5 Programmable Logic Controllers (PLCs): Basics, Types Functional Block Diagram (FBD) is a simple and graphical method to program multiple functions in PLC. PLCOpen has described using FBD in the standard IEC 61131-3. A function block is a program instruction unit which, when executed, yields one or more output values. Block Diagram | Block Diagram in Control System Block Diagram in Contol System. By using block diagrams when examining larger systems, attention can be focused on a smaller number of elements or subsystems whose properties may already be known doing this, a set of individual blocks representing the various elements or subsystems is formed, and these blocks are interconnected to represent the whole system.