What happens when the TOF instruction is disabled in a PLC program?

When the TOF (Timer Off Delay) instruction is disabled in a PLC program, the accumulated value indeed continues to increase as long as the timer's enabling conditions are met. The TOF instruction serves to keep track of elapsed time after a specified condition has turned off, and if it is disabled, the timer does not stop accumulating time. This behavior is significant in applications where a continuous count of elapsed time is critical even when the timer’s overall function is temporarily halted.

In the context of a programming or control environment, disabling the TOF instruction wouldn't reset the accumulated value—it merely suggests that the function of the timer is suspended while the accumulation may still proceed depending on the logic flow. Thus, the understanding of what occurs when the instruction is disabled enhances the operator's ability to anticipate how the system behaves and maintains its timing operations effectively.