The timer of S7- 1200 is IEC timer, and the number of timers that can be used in user programs is only limited by the memory capacity of CPU. To use the timer, you need to use the background data block or DB block variable related to the timer, the data type is IEC_TIMER (or TP_TIME, TOF_TIME, TOR _ time), and the above different variables represent different timers. Note: IEC timer of S7- 1200 has no timer number (that is, there are no timers with timer numbers of T0, T37, etc.).