Statement List (STL) - DCE FEL ČVUT v Praze

Time Base
Timer Instructions
Bits 12 and 13 of the timer word contain the time base in binary code. The time base
defines the interval at which the time value is decremented by one unit. The smallest
time base is 10 ms; the largest is 10 s.
Time Base Binary Code for the Time Base
10 ms 00
100 ms 01
1 s 10
10 s 11
Values that exceed 2h46m30s are not accepted. A value whose resolution is too
high for the range limits (for example, 2h10ms) is truncated down to a valid
resolution. The general format for S5TIME has limits to range and resolution as
shown below:
Resolution Range
0.01 second 10MS to 9S_990MS
0.1 second 100MS to 1M_39S_900MS
1 second 1S to 16M_39S
10 seconds 10S to 2H_46M_30S
Bit Configuration in ACCU 1
When a timer is started, the contents of ACCU1 are used as the time value. Bits 0
through 11 of the ACCU1-L hold the time value in binary coded decimal format (BCD
format: each set of four bits contains the binary code for one decimal value). Bits 12
and 13 hold the time base in binary code.
The following figure shows the contents of ACCU1-L loaded with timer value 127 and
a time base of 1 second:
15... ...8 7... ...0
x x 1 0 0 0 0 1 0 0 1 0 0 1 1 1
Time base
1 second
1 2 7
Time value in BCD (0 to 999)
Irrelevant: These bits are ignored when the timer is started.
Statement List (STL) for S7-300 and S7-400 Programming
A5E00706960-01 12-3