Cp Diagnostics - Siemens SIMATIC S7-1200 CP 1243-8 IRC Operating Instructions Manual

Configuration
4.11 Communication with the CPU
● Frame memory size
Here, you set the size of the frame memory for events (send buffer).
The size of the frame memory is divided equally among all configured communications
partners. You will find the size of the frame memory in the section Performance data and
configuration limits (Page 22).
You will find details of how the send buffer works (storing and sending events) as well as
the options for transferring data in the section Process image, type of transmission, event
classes (Page 144).
Watchdog bit
● CP monitoring
Via the watchdog bit the CPU can be informed of the status of the telecontrol
communication of the CP.
CP time of day
● CP time to CPU
Using this function, the CP can make its time of day available to the CPU.
You will find details in the STEP 7 information system.
4.11.2

CP diagnostics

The functions are supported by a CP as of firmware version V3.
CP diagnostics
With the parameter group, you have the option of reading out advanced diagnostics data
from the CP using PLC tags.
● Enable advanced CP diagnostics
Enable the option to be able to use advanced CP diagnostics.
If the option is enabled, at least the "Diagnostics trigger tag" must be configured.
The following PLC tags for the individual items of diagnostics data can be enabled
selectively.
● Diagnostics trigger tag
If the PLC tag (BOOL) from the user program of the CPU is set to 1, the CP updates the
values of the PLC tags that can then be configured for the advanced diagnostics.
After writing the current values to the following PLC tags, the CP sets the "Diagnostics
trigger tag" to 0 signaling the CPU that the updated values can be read from the PLC
tags.
Note
Fast setting of the diagnostics trigger variable
Triggers must not be set faster than a minimum interval of 500 milliseconds.
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Operating Instructions, 02/2018, C79000-G8976-C385-03
CP 1243-8 IRC