Communication Functions
Work Area
In every automation system there is a linear work area, in which an increase in the
communication load will lead to an increase in the data throughput. This will lead to
clear reaction times, which are usually acceptable for the respective automation
task.
If there is further increase in the communication load, the throughput will enter the
saturation area. The amount of the requests may no longer be processed in the
automation system whithin required the response time. The data throughput will
reach a maximum and the reaction time will increase exponentially, see diagram
below.
The data throughput will decrease in part due to additional internal device load.
Data throughput
Figure 8-14
Response time
Figure 8-15
8-22
Communication load
Data throughput via communication load (basic trend)
Communication load
Response time via communication load (basic trend)
Standard CPU
H-CPU
Standard CPU
H-CPU
Automation System S7-400H Fault-tolerant Systems
A5E00068197-07