Communication Performance; Definition Of Communication Load - Siemens SIMATIC S7-400H Manual

8.6

Communication Performance

The following explanation applies to:
•
CPU 414-4H with order number 6ES7 414-4HJ00-0AB0, all releases.
•
CPU 417-4H with order number 6ES7 417-4HL01-0AB0, all releases.
In an H-system the communication performance (response time and data
throughput) during redundant operation is considerably lower in an H-CPU during
single operation or in a standard CPU.
This description is meant to provide the assessment criteria, with which you can
evaluate the effects of the different communication mechanisms on the
communication performance.

Definition of Communication Load

Communication is the sum of all jobs sent to the CPU via the communication
mechanisms per second plus the jobs and messages output by the CPU.
The bigger the communication load, the larger the CPU response time, this means
the CPU requires a longer period of time to respond to a job (e.g., read job) or to
output jobs and messages.
Automation System S7-400H Fault-tolerant Systems
A5E00068197-07
Communication Functions
8-21