Diagnostics Via The Diagnostic Buffer Of The Cp 440 - Siemens SIMATIC S7-400 Equipment Manual

Diagnostics with the CP 440

8.4 Diagnostics via the diagnostic buffer of the CP 440

8.4 Diagnostics via the diagnostic buffer of the CP 440
Diagnostic Buffer of the CP 440
The CP 440 has its own diagnostic buffer, in which all the diagnostic events of the CP 440 are
entered in the order in which they occur.
The following are displayed in the diagnostic buffer of the CP 440:
• Initialization and parameter errors
• Errors during execution of a CPU request
• Data transmission errors (send and receive errors)
The diagnostic buffer allows the causes of errors in point-to-point communication to be
evaluated subsequently in order, for example, to determine the causes of a STOP of the CP 440
or to trace the occurrence of individual diagnostic events.
Note
The diagnostic buffer is a ring buffer for a maximum of 10 diagnostic entries. When the
diagnostic buffer is full, the oldest entry is deleted when a new entry is made in it. This means
that the most recent entry is always first. The contents of the diagnostics buffer are lost in the
event of a POWER OFF or when the CP 440 is reconfigured.
It is not possible to display the time.
Reading the Diagnostic Buffer at the Programming Device
The contents of the diagnostic buffer of the CP 440 can be read by means of the STEP 7
information functions.
All the user-relevant information in the CP diagnostic buffer is displayed to you in the "Diagnostic
Buffer" dialog box on the "Module Information" tab. You can access the "Module Information" tab
under STEP 7 from SIMATIC Manager.
Prerequisite: In order to obtain the status of the module, there must be an on-line connection
from the programming device to the programmable controller (on-line view in the project
window).
To do this, proceed as follows:
1. Open the relevant SIMATIC 400 station (double-click or select menu command Edit > Open).
2. Then open the "Hardware" object (double-click or select menu command Edit > Open).
Result:The window containing the configuration table appears.
3. Select the CP 440 in the configuration table.
104
Point-to-point connection CP 440 Installation and Parameter Assignment
Equipment Manual, 03/2022, A5E00057742-AE