Siemens Simatic S7-1500R - Technical Specifications; Status;Control; Forcing; Diagnostic Buffer

Cyclic program execution
3.4 Response time for cyclic and time-driven program execution
Cycle and response times
44 Function Manual, 10/2018, A5E03461504-AD
Update time of the backplane bus for ET 200SP CPUs
The following table shows the central (typical) update times of the backplane bus for the
ET 200SP CPUs.
Table 3- 6 Update time of the ET 200SP CPUs
Update time of the CPU
ET 200SP
1510SP(F)-1 PN
1512SP(F)-1 PN
1515SP(F)-PC
Update time for
central I/O
250 μs to 1 ms, depending on number and type of central I/O modules
1
1
The duration of the update time depends on the number of the I/O modules and their type (ST, HF, HS). The update
time is set at 1 ms for a max. central I/O configuration with standard I/O modules. You can reduce the update time down
to 250 μs, for example, by using HF I/O modules and by reducing the number of modules.
The table below is an orientation guide. It shows the approximate relationship between the
number of ET 200SP I/O modules and the bus cycle that is used. As an example, 8 bytes of
I/O data per I/O module are assumed in the table.
Number of ET 200SP I/O modules
Input data (bytes)
Output data (bytes)
Used bus cycle (μs)
8
64
64
250
16
128
128
250
24
192
192
281.25
32
256
256
312.5
40
320
320
343.75
48
384
384
375
56
448
448
406.25
64
512
512
437.5
For I/O modules with more than 32 bytes of I/O data, the bus cycle is calculated with an I/O
module of 32 bytes. In this case the I/O module requires multiple bus cycles to update its I/O
data.