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Cycle and Response Times
7-4
ET 200S Interface Module IM 151/CPU
A5E00058783-01
User Program Scanning Time:
The user program scanning time is made up of the sum of the execution times for
the instructions and SFCs called. These execution times can be found in the
Instruction List. You also have to multiply the user program scanning time by a
basic module-specific factor.
In the IM 151/CPU, this factor depends on the following:
Table 7-3
Dependency of the User Program Scanning Time
Dependency
Range
The number of modules inserted
0 to 63
The volume of data transferred via the
PROFIBUS-DP between the DP master and DP
slave (input data + output data)
0 to 128 bytes
The volume of data
obtained
through direct
communication
0 to 256 bytes
You can calculate the factor for your application approximately using the following
rule of thumb for the IM 151/CPU
1,1
+
0.0055 x number of modules
+
0.0022 x number of bytes transfered (PROFIBUS-DP)
+
0.0011 x number of bytes obtained (direct communication)
=
Multiplier for your user program
S7 Timers
The S7 timers are updated every 10 ms.
To include the S7 timers in the calculation of the cycle and response times of the
IM 151/CPU, multiply the number of active S7 timers by 8
µ
s.
Table 7-4
Updating the S7 Timers
Sequence
IM 151/CPU
Updating the S7 timers (every 10 ms)
Number of simultaneously active
S7 timers
8
s
Summary of Contents for SIMATIC IM 151/CPU
Page 6: ...Important Information vi ET 200S Interface Module IM 151 CPU A5E00058783 01 ...
Page 14: ...Contents xiv ET 200S Interface Module IM 151 CPU A5E00058783 01 ...
Page 42: ...ET 200S in the PROFIBUS Network 3 12 ET 200S Interface Module IM 151 CPU A5E00058783 01 ...
Page 68: ...Commissioning and Diagnostics 4 26 ET 200S Interface Module IM 151 CPU A5E00058783 01 ...
Page 98: ...Technical Specifications 6 8 ET 200S Interface Module IM 151 CPU A5E00058783 01 ...
Page 108: ...Cycle and Response Times 7 10 ET 200S Interface Module IM 151 CPU A5E00058783 01 ...
Page 190: ...Execution Times of the SFCs and SFBs C 4 ET 200S Interface Module IM 151 CPU A5E00058783 01 ...
Page 196: ...Migration of the IM 151 CPU D 6 ET 200S Interface Module IM 151 CPU A5E00058783 01 ...