Configuration
4.7 Communication with the CPU
CP 154xSP-1
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Operating Instructions, 12/2019, C79000-G8976-C426-05
CP time
●
CP time to CPU
The function allows the CPU to read the time of day of the CP. Using this approach, the
CP can synchronize the CPU time.
Procedure:
–
The CPU sets the input "Time trigger variable" (BOOL) to 1 with the user program.
–
The CP then writes its time to the "CP time variable" (DTL) and resets the "Time
trigger variable" value to 0.
–
The user program reads the "CP time variable" to set the CPU time.
Recommendation:
Set the "Time trigger variable" no more frequently than once per second to avoid placing
an unnecessary communication load on the backplane bus.
Note
Refer to the information in the section Time-of-day synchronization (Page 57).
CP diagnostics
With the parameter group, you have the option of reading out advanced diagnostics data
from the CP.
●
Enable advanced CP diagnostics
Enable the option 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 following PLC tags for the advanced diagnostics.
After writing the current values to the following PLC tags, the CP sets the "Diagnostics
trigger tag" to 0, signaling to the CPU that the updated values can be read from the PLC
tags.
Note
Fast setting of the diagnostics trigger tag
Trigger should not be set more often than once per second.
Variable for CP 1542SP-1 and CP 1543SP-1:
●
Current IP address
PLC tag (data type String) for the current IP address of the interface of the CP.