Online functionality
8.5 Displaying the diagnostic events
Easy Book
94
Manual, 05/2009, A5E02486774-01
8.5
Displaying the diagnostic events
The CPU supports a diagnostic buffer which contains an entry for each diagnostic event.
Each entry includes a date and time the event occurred, an event category, and an event
description. The entries are displayed in chronological order with the most recent event at
the top.
To access the diagnostic buffer, you must be online.
While the CPU maintains power,
up to 50 most recent events are
available in this log. When the log
is full, a new event replaces the
oldest event in the log. When
power is lost, the ten most recent
events are saved.
The following types of events are recorded in the diagnostics buffer:
●
Each system diagnostic event; for example, CPU errors and module errors
●
Each state change of the CPU (each power up, each transition to STOP, each transition
to RUN)
●
Each change to a configured object except changes issued by the CPU and the user
program
8.6
Using a watch table for monitoring the CPU
A watch table allows you to perform monitoring and control functions on data points as the
CPU executes your program. These data points can be inputs (I), outputs (Q), peripheral
inputs or outputs (such as "On:P", "I 3.4:P" or "Q3.4:P"), M memory, or a DB depending on
the monitor or control function.
The monitoring function does not change the program sequence. It presents you with
information about the program sequence and the data of the program in the CPU. You can
also use the "Modify", "Force", and "Force and enable outputs in STOP" functions to test the
execution of your user program.