Siemens Simatic S7-200 CPU 210 System Manual page 123

Execution Times for STL Instructions
Table E-1 lists the basic execution times of the STL instructions for the CPU 210. The
calculation of the basic execution time for an STL instruction shows the time required for
executing the logic, or function, of the instruction when power flow is present (where the
top-of-stack value is ON or 1).
For some instructions, the execution of that function is conditional upon the presence of
power flow: the CPU performs the function only when power flow is present to the instruction
(when the top-of-stack value is ON or 1).
The overhead for the CPU 210 is 140 s per scan. There is also an additional overhead that
is associated with the system clock: add 60 s for every 1 ms counted by the system clock.
Table E-1
Instruction
=
A
ALD
AN
AW < =
AW=
AW > =
CTUD
DECW
DISI
ED
ENI
EU
INCW
INT
JMP
LBL
S7-200 Programmable Controller, CPU 210
C79000-G7076-C235-01
Execution Times for the STL Instructions (in µs)
Description
Output valid for Q, M
And valid for I, M, SM
And Load
And Not valid for I, M, SM
And Word if less than or equal
And Word if equal
And Word if greater than or equal
Up/Down Counter
Decrement Word
Disable Interrupts
Edge Down (Negative Transition)
Enable Interrupts
Edge Up (Positive Transition)
Increment Word
Interrupt Routine
Add 110 µs if the interrupt routine uses any of the
following instructions:
MOVW
LDW<=, LDW>=, LDW=
OW<=, ,OW>=, OW=
AW<=, AW>=, AW=
Jump to Label
Label
E
On (µs) Off (µs)
120 120
110 110
60 60
80 80
300 300
300 300
300 300
110 100
140 70
60 60
120 120
60 60
110 110
140 70
30
Not applicable
70 70
0 0
E-1