Siemens CPU 31 Series Technical Data Manual page 91

Table 5-4
Const.
C
A
B
D
(DP only)
P
(PROFIN
ET only)
* + 60 μs per rack
** + 21 μs per rack
Extending the user program processing time
In addition to actually working through the user program, your CPU's operating system also
runs a number of processes in parallel
(such as timer management for the core operating system). These processes extend the
processing time of the user program. The table below lists the multiplication factors required
to calculate your user program processing time.
Table 5-5
CPU
312C
313C
313C-2DP
313C-PtP
314C-2DP
314C-2PtP
312
314
315
317
319
CPU 31xC and CPU 31x, Technical Data
Manual, 01/2006 Edition, A5E00105475-06
CPU 31x: Data for calculating the process image (PI) transfer time
Components CPU 312
Base load 150 μs
Per byte in the 37 μs
rack 0
per byte in module -
racks 1 to 3 *
Per word in the DP -
area for the
integrated DP
interface
per WORD in the -
PROFINET area
for the integrated
PROFINET
interface
Extending the user program processing time
Factor
1,06
1,10
1,10
1,06
1,10
1,09
1,06
1,10
1,10
1,07
1,05
CPU 314 CPU 315
100 μs 100 μs
35 μs 37 μs
43 μs* 47 μs*
- 2,5 μs
- 46 μs
Cycle and reaction times
5.2 Cycle time
CPU 317 CPU 319
50 μs 2 μs
15 μs 15 μs
25 μs* 22 μs**
2,5 μs 2,5 μs
46 μs 2,5 μs
5-5