output module plc programming optimization techniques: improved program running speed

1 : According to the actual needs of the project , functional block planning, writing subroutines
In the PLC program subroutines are relatively  Nanda Programmable industrial controller plc independent control purposes for a number of specific preparation . CALL subroutine call instruction is executed , such as when a subroutine call if the condition is not met , the program scans performed in the main program only , and not to scan this subroutine , which reduces scan time unnecessarily . 2 : Use a word or double word reportedly gave DO -point method to control output
In the application of PLC will usually have a lot of output control , with the word, or double word reportedly gave DO -point method to control the output can improve the speed , as long as according to the requirements of practical application, a reasonable allocation of the output address , change control output control word , you can greatly reducing the number of steps PLC program execution , thus speeding up the running Nanda china industrial automation plc  speed of the PLC .
3 : Pulse trigger SET, RESET
  PLC, using the SET command is executed only once , do not run this command every scan , it is suitable for use with pulse output (PLS / PLF) instructions for use . Some engineers ignore this problem , the use of conventional methods to drive the SET command , inadvertently increasing the PLC program scan running time.