Siemens SIMATIC S5-95F Manual page 196

STEP 5 Operations
Updating the Timers
The operating system of the S5-95F ensures that the same times or timer statuses are present in
both subunits when a timer is scanned.
Note
The timers are divided into two areas T 0 to T 63 and T 64 to T 127. Please note that
the timers are updated at different times:
• Timers T 0 to T 63 are updated by the operating system always when you scan the
timer in the control program.
• Timers T 64 to T 127 are updated by the operating system always prior to
processing of OB1. The timers are not updated during the start-up organization
blocks OB21/OB22.
Loading a Time
Timer operations call internal timers.
When a timer operation is started, the word in ACCU 1 is used as a time value. You must therefore
first specify time values in the accumulator.
You can load a timer with any of the following data types:
KT constant time value
or
DW data word
IW input word
QW output word
FW flag word
Loading a Constant Time Value:
The following example shows how you can load a time value of 40 s.
L KT 40.2
Key for Time Base
Base 0
Factor 0.01 s
8-16
These data types must be
in BCD code.
Operation
Operand
Coded time base (0 to 3)
Time (0 to 999)
1 2
0.1 s 1 s
3
10 s
S5-95F
EWA 4NEB 812 6210-02