Siemens CP 1243-7 LTE Operating Instructions Manual page 63

● Max. number of read jobs
Maximum number of low-priority read jobs from the CPU memory area within a CPU scan
cycle.
● 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 communications partners. You
will find the size of the frame memory in the section Configuration limits and performance
data (Page 18).
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, triggers (Page 84).
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
● CP time to CPU
Using this function, the CP can synchronize the CPU clock.
You will find details in the STEP 7 information system.
CP diagnostics
In the parameter group "CP diagnostics", you have the option of reading out advanced
diagnostics data from the CP using PLC tags.
● Diagnostics trigger tag
If you want to use advanced CP diagnostics, you need to configure the "Diagnostics
trigger tag".
If the user program of the CPU sets the PLC tag "Diagnostics trigger tag" (BOOL) to 1,
the CP updates the values of the configured PLC tags for advanced diagnostics. After
writing the current values to the PLC tags for advanced diagnostics, the CP sets the
"Diagnostics trigger tag" to 0 signaling the CPU that the updated values can be read from
the PLC tags.
Reading out the following diagnostics data can be enabled selectively:
Note
Fast setting of the diagnostics trigger variable
Triggers must not be set faster than a minimum interval of 500 milliseconds.
CP 1243-7 LTE
Operating Instructions, 04/2017, C79000-G8976-C381-03
Configuration
4.10 Communication with the CPU
63