A graphical programming language which is a representation of function blocks and logic gates is known as functional block diagram.
When the PLC was created, logic gates and their use in integrated logic circuits were well understood. Using a specialized graphics painting application, connection lines are used to connect the various symbols in Function Block programming.
The machine language equivalent can be generated automatically based on a schematic like this one. The figure is an example of a typical Functional Block Diagram (FBD). Three key elements of a Functional Block Diagram.
- Identification of the Input
- Description of the logic that will take place in the Module,
- Description of the Output
For there to be a high level of output at C, the input at A needs to be high while the input at B needs to be low. Only when both of the AND gate’s inputs are high or true, the output of the AND gate will be high or true. The flow of control may be followed quite easily using this graphical representation of the technique.
Placing blocks in the circuit
The FBD programming language requires that we arrange blocks in the form of a circuit diagram, connect the blocks using wires, and may or may not include descriptive labels and comments. There are three distinct sorts of blocks represented by icons located on the Tools.
Constants Basic Functions Special Functions On the icon for the Constants in [FBD], a row with eleven icons displays as follows:
The functions I, Input, Q, Output, and M, Memory location or flag, are the most often used. A row of eight icons appears when operating the Basic Functions icon in [FBD]:
The graphic above shows six of these without an arrow. The two arrow-shaped icons stand for edge triggering.
How ladder logic differs from function block diagram?
Ladder Logic should be read from left to right and top to bottom. Many lines of ladder logic can be essentially transformed into boxes using function block diagrams.
Advantages of Functional Block Diagram
More popularity is being seen for the usage of function blocks in programming programmable logic controllers (PLCs). The main advantages of employing function blocks diagram are:
- Less training requirement
- Outstanding motion controls
- Reading visual blocks is simpler
- Merge codes to save time