Temporary End (TND) Instruction in PLC Ladder Logic

Temporary End (TND) instruction, when its rung is true:

  • Stops the processor from scanning the rest of the program file

  • Updates the I/O, and

  • Resumes scanning at rung 0 of the main program (file 2)

If this instruction’s rung is false, the processor continues the scan until the next TND instruction or the END statement.

Use this TND instruction to progressively debug a program, or conditionally omit the balance of your current program file or subroutines