GSK 980TC3 Series, Manual

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GSK980TC3 Series Bus Turning CNC system PLC, Installation and Connection User Manual
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Programming
2.4 Sequence Programming Structure
The ladder diagram is compiled with sequence in the traditional PLC. It owns the following
advantages in the ladder diagram language allowing the structured programming:
1. The program is easy to comprehend and compile.
2. It is more convenient to find the faults during the programming.
3. It is easy to find some reasons when the operation malfunction occurs.
The methods of the main structure programming are shown below:
1) Sub-program
The subprogram is regarded as a treatment unit based on the ladder diagram.
Task A
Task B
A
A
C
B
C
.
.
.
.
Fig. 2-4-1
2) Nesting
One subprogram can be performed the task by calling another one.
Task A
Task B
Main program
Task A1
Task An
Task A11
Task A12
Subprogram 1 Subprogram 2
Fig. 2-4-2
3) Conditional branch
The main program is performed circularly, and checks whether its conditions are suitable. The
corresponding subprograms are performed under these conditions, vice versa.