PLC concepts
5.1 Execution of the user program
S7-1200 Programmable controller
114 System Manual, V4.2, 09/2016, A5E02486680-AK
The CPU supports a diagnostics buffer that 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. 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 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)
To access the diagnostics buffer (Page 1322), you must be online. From the "Online &
diagnostics" view, locate the diagnostics buffer under "Diagnostics > Diagnostics buffer".
Reducing the number of security diagnostic events
Some security events generate repeated entries in the diagnostics buffer. These messages
can fill up the diagnostics buffer and potentially obscure other event messages. You can
configure the PLC to limit the number of diagnostic messages from security events. You
make selections in the device configuration of the CPU based on the time interval in which
you want to suppress recurring messages:
If you choose to summarize security events within a time interval, you have the choice of
setting a time interval in seconds, minutes, or hours, and a numerical value in the range 1 ..
255.
If you choose to restrict security events, you will be restricting these types of events:
● Going online with the correct or incorrect password
● Manipulated communications data detected
● Manipulated data detected on memory card
● Manipulated firmware update file detected
● Changed protection level (access protection) downloaded to the CPU
● Password legitimization restricted or enabled (by instruction or CPU display)
● Online access denied due to the possible number of simultaneous access attempts being
exceeded
● Timeout when an existing online connection is inactive
● Logging in to the Web server with the correct or incorrect password
To Next Page
Loading...
