On-Delay Timer Retentive Timers

Inputs/Outputs Operands Data Types
Txxx Constant (T0 T255) WORD
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, T, C, AC, Constant, *VD, *AC, *LD INT

Memory Ranges ENO Errors Instruction Support for S7-200 CPUs SIMATIC/International Mnemonics
The Retentive On-Delay Timer (TONR) instruction counts time when the enabling input is ON. When the current value (Txxx) is greater than or equal to the preset time (PT), the timer bit is ON.

The current value of the Retentive On-Delay timer is maintained when the input is OFF. You can use the Retentive On-Delay timer to accumulate time for multiple periods of the input ON. A Reset instruction (R) is used to clear the current value of the Retentive On-Delay timer.

This timer continues counting after the Preset is reached, and it stops counting at the maximum value of 32767.

TON, TONR, and TOF 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

TONR 1 ms 32.767 s T0, T64

10 ms 327.67 s T1-T4, T65-T68

100 ms 3276.7 s T5-T31, T69-T95

TON, TOF 1 ms 32.767 s T32, T96

10 ms 327.67 s T33-T36, T97-T100

100 ms 3276.7 s T37-T63, T101-T255


The Reset (R) instruction can be used to reset any timer. The Reset instruction performs the following operations:

Timer Bit = OFF and Timer Current = 0

The TONR timer can only be reset by the Reset instruction.


See Also:

Understanding S7-200 Timer Instructions