Siemens SIMATIC IM 151/CPU User Manual

Instruction List
B-7
ET 200S Interface Module IM 151/CPU
A5E00058783-01
B.5 Execution Times with Indirect Addressing
Two-Part Statement
A statement with indirectly addressed instructions consists of 2 parts:
Part 1: Loading the Address of the Address ID
Part 2: Executing the Instruction
In other words, you must calculate the execution time of a statement with indirectly
addressed instructions from these two parts.
Calculating the Execution Time
The total execution time is calculated as follows:
Time required for loading the address
+ execution time of the instruction
= Total execution time of the instruction
The execution times given in Appendix B.6 and the following chapters are the
execution times for the second part of a statement (i.e. for the actual execution of
an instruction).
You then have to add the time required for loading the address of the instruction to
this execution time.
Loading an Address
The execution time for loading the address of the instruction from the various
areas is shown in the following table.
Address Is In ... Execution Time in s
Memory marker area M
Word
Double word
0.8
2.1
Data block DB/DX
Word
Double word
3.0
4.1
Local data area L
Word
Double word
0.9
2.2
AR1/AR2 (area-internal) 1.7
AR1/AR2 (area-crossing) 3.2

Siemens SIMATIC IM 151/CPU Specifications

General

Brand	Siemens
Model	SIMATIC IM 151/CPU
Category	Control Unit
Language	English