TechTalk - RSLogix5000 : TOF Characteristics

TechTalk - RSLogix5000 : TOF Characteristics

Xybernetics RSLogix5000 : The TOF Instruction

The next few screen shots illustrates the life-cycle of a TOF function block. Notice when the “EN” and “DN” reacts as “Accum” approaches “Preset” value (of 60000).

TOF instruction starts counting up as “Local:1:I.Data.8” is de-energized. Note that “EN” is de-energized while “DN” is energized.
Xybernetics RSLogix5000 : The TOF Instruction

TOF counter elapsed 15652 milliseconds.
Xybernetics RSLogix5000 : The TOF Instruction

TOF counter elapsed 34291 milliseconds.
Xybernetics RSLogix5000 : The TOF Instruction

TOF instruction has reached/exceeded “Preset” value (of 60000). Note that both the “EN” and “DN” is de-energized.
Xybernetics RSLogix5000 : The TOF Instruction

When the “Local:1:I.Data.8” is energized again, TOF instruction “Accum” is reset to zero and both “EN” and “DN” are energized.
Xybernetics RSLogix5000 : The TOF Instruction

The acronym “EN” and “DN” stands for “Enable” and “Done” respectively. We can utilized these TOF instructions property to program our logic. Foe example, we can use this for debounce timer. That is, if 60000 milliseconds has elapsed and the IO “Local:1:I.Data.8” is still de-energized, then we can use this to trigger alarms, ESD string, etc.

We can access the TOF instruction property via the following methods.
“LSLL_60.Debounce[0].EN” for enable and “LSLL_60.Debounce[0].DN” for done.
Cheers!