S5 Timer Calculator
Convert Siemens S5 KT timer values to seconds, IEC format, and S7 code instantly.
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Result
Enter a KT value or seconds to see results.
S5 Timer Types & S7 Equivalents
| S5 | Function | S7 Function | IEC Type |
|---|---|---|---|
| SI | Pulse | S_PULSE | TP |
| SE | Extended Pulse | S_PEXT | TP |
| SD | On-Delay | S_ODT | TON |
| SS | Retentive On-Delay | S_ODTS | TON |
| SA | Off-Delay | S_OFFDT | TOF |
Time Base Reference
| Code | Resolution | Max Value | Max Duration |
|---|---|---|---|
| 0 | 10 ms | 999 | 9.99 s(9.99 s) |
| 1 | 100 ms | 999 | 99.9 s(1 min 39.9 s) |
| 2 | 1 s | 999 | 999 s(16 min 39 s) |
| 3 | 10 s | 999 | 9990 s(2 h 46 min 30 s) |
Frequently Asked Questions
What does KT 030.2 mean in Siemens S5?
KT 030.2 is a timer constant in STEP 5 format. 'KT' stands for 'Konstante Timer' (timer constant). The value 030 is the BCD-encoded count (30), and .2 indicates time base 2 (1-second resolution). So KT 030.2 = 30 × 1 s = 30 seconds. The four time bases are: .0 = 10 ms, .1 = 100 ms, .2 = 1 s, .3 = 10 s.
How does S5 encode timer values in BCD format?
S5 timers are stored as a 16-bit word in Binary Coded Decimal (BCD) format. Bits 13–12 hold the time base (0–3), bits 11–8 the hundreds digit, bits 7–4 the tens digit, and bits 3–0 the ones digit. Bits 15–14 are unused. For example, KT 030.2 encodes as 0x2030: time base 2 in bits 13–12, value 030 across three BCD nibbles.
How do I convert S5 timers to S7?
Replace the S5 timer instruction with its IEC equivalent: SI/SE → TP (Pulse), SD/SS → TON (On-Delay), SA → TOF (Off-Delay). Convert the KT constant to IEC time format — e.g., KT 030.2 becomes T#30s. In S7 SCL, call the IEC timer function block with the converted time value.
What are the S5 timer time bases?
S5 timers use four time bases that determine resolution: 0 = 10 ms (max 9.99 s), 1 = 100 ms (max 99.9 s), 2 = 1 s (max 999 s), 3 = 10 s (max 9990 s ≈ 2 h 46 min). The time base is specified after the decimal point in the KT constant.
What is the maximum S5 timer duration?
The maximum S5 timer duration is 9,990 seconds (2 hours, 46 minutes, 30 seconds), set with KT 999.3 — value 999 at time base 3 (10 s resolution). For longer durations, chain multiple timers or combine timers with counters.
Need to convert an entire S5 program?
PLCcheck Pro analyzes your complete S5 code — all timers, counters, addresses, and function blocks — and generates S7 SCL with full documentation.
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