|Txxx||Constant (T32 – T63, T97 – T255)||TOF|
|IN (LAD)||Power Flow||BOOL|
|IN (FBD)||I, Q, M, SM, T, C, V, S, L, Power Flow||BOOL|
|PT||VW, IW, QW, MW, SW, SMW, LW, AIW, AC, Constant, *VD, *AC, *LD||INT|
|Q||I, Q, M, SM, V, S, L||BOOL|
|ET||VW, IW, QW, MW, SW, SMW, LW, AQW, AC, *VD, *AC, *LD||INT|
|Memory Ranges||ENO||Errors||Instruction Support for S7-200 CPUs||SIMATIC/International Mnemonics|
|The Off-Delay Timer (TOF) is used to delay the setting of an output false for a fixed period of time after the input goes false. It times up to the preset value when the enabling input (IN) goes false. When the elapsed time (ET) is greater than or equal to the preset time (PT), the timer output bit (Q) turns on.
Once the preset is reached, the timer output bit turns false and the elapsed time is maintained until the enabling input (IN) transitions to true. If the enabling input (IN) transitions to false for a period of time shorter than the preset time (PT), the output bit remains true.
TON, TOF, and TP timers are available in three resolutions. The resolution is determined by the timer number as shown in the chart below. Each count of the current value is a multiple of the time base. For example, a count of 50 on a 10-ms timer represents 500 ms.
Timer Type Resolution Maximum Value Timer Number
TON, TOF, 1 ms 32.767 s T32, T96
TP 10 ms 327.67 s T33-T36, T97-T100
100 ms 3276.7 s T37-T63, T101-T255
You cannot share the same timer numbers for TOF, TP, and TON. For example, you cannot have both a TON T32 and a TOF T32.