Options For Displaying And Evaluating Errors; Types Of Error; Synchronous Errors; Asynchronous Errors - Siemens SIMATIC FM 351 Manual

Diagnostics
11.1

Options for Displaying and Evaluating Errors

You can obtain information on errors in the following ways:
Observing the error LEDs on the module.
The meaning of the error LEDs is explained in Section 11.3 (page 11-3).
Connect your programming device with the CPU and open the error evaluation
dialog of the configuration software. The current (error) state of the module is
displayed along with the error class, error number and a plain language
explanation. When necessary, you can update the display by clicking the
"Update" button.
The causes of the displayed error messages and possible remedies are
explained in the error list in Appendix C.5 (page C-15).
Write a detailed error evaluation routine in your user program (see Section 11.4,
page 11-4) or a reaction to a diagnostic interrupt (see Section 11.4 and 11.7).
To display errors on an OP: Read out the diagnostic buffer of the module
cyclically in your user program (see Figure 11-2). Evaluate the diagnostic DB on
the OP. The meaning of the error class and error number is explained in the
error list in Appendix C.5 (page C-15).
Deleting the Diagnostic Buffer
To give you a better chronological overview of the error messages, the FM 351
allows you to delete the diagnostic buffer completely. This is, however, only
possible when a positioning operation has been completed and when you have set
parameters for the channel.
11.2

Types of Error

11.2.1

Synchronous Errors

These errors occur at the same time as a job or the start of a positioning operation.
Synchronous errors are operator errors (error class 2), data errors (error class 4),
machine data errors (error class 5), incremental dimension table errors (error class
6) (refer to the error list in Appendix C.5, page C-15).
11.2.2

Asynchronous Errors

These errors occur during operation as a result of external events. These errors
trigger a diagnostic interrupt. Asynchronous errors include operating errors (error
class 1) and diagnostic errors (error class 128) (refer to the error list in Appendix
C.5, page C-15).
11-2
FM 351 Positioning Module
C79000-G7076-C351-02