Extended Diagnostics Of The As-Interface Master; List Of As-Interface Slaves, Which Have Initiated Configuration Errors (Lcs); Protocol Analysis: Counter For Transmission Errors For Data Telegrams; Offline Phase In The Case Of Configuration Errors - WAGO -I/O-SYSTEM 750 Series Manual

2.1.1.10

Extended diagnostics of the AS-Interface master

The extended diagnostics can be used to localize intermittent configuration
errors as well as assessing the quality of the data transmission on the AS-
Interface bus.
2.1.1.10.1 List of AS-Interface slaves, which have initiated configuration errors
(LCS)
In order to diagnose the causes, which are responsible for short-term
configuration errors on the AS-Interface network, along with the list of
projected slaves (LPS), the list of detected slaves (LDS) and the list of active
slaves (LAS), AS-Interface masters with extended diagnostics functionality
also manage an additional list of slaves, which have initiated a configuration
error (LCS, List of Corrupted Slaves). In this list appear all slaves, which
have caused at least one short-term configuration error since the last time the
list was read or since the master was switched on. Furthermore, short-term
voltage dips on the AS-Interface network are also displayed in the LCS in
place of slave 0.
Note
The LCS is deleted again each time a read process is carried out.
2.1.1.10.2

Protocol analysis: Counter for transmission errors for data telegrams

Masters with extended diagnostics provide a counter for each slave for
telegram repeats, which is incremented for every transmission error in the case
of data telegrams. By this means, the quality of the transmission can be
assessed even when only individual telegrams are faulty and the slave would
therefore never initiate a configuration error.
Note
The status of the counters is read out via the appropriate host interface and
reset with each read access. The highest valid instantaneous status of the
counter is 254. A count of 255 indicates a counter overflow.
2.1.1.10.3

Offline phase in the case of configuration errors

Masters with extended diagnostics provide the option of placing themselves in
the offline state in the case of a configuration error, hence placing the AS-
Interface network in a safe operating state. It is thus possible to respond more
quickly to configuration errors and the host is relieved of this task. If problems
occur on the AS-Interface, the masters can automatically switch the AS-
Interface network into a safe state.
WAGO-I/O-SYSTEM 750
I/O Modules
750-655 [AS-Interface master module]
Extended diagnostics of the AS-Interface master
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