Mitsubishi MELSEC-A Series User Manual page 26

4. FUNCTIONS
MELSEGA
(4) Communication fault area
This area stores the details of any fault that occurs while the
AJ71 PB92 is engaged in communication. For this area, either the
fixed type or ring type can selected by switching the communication
fault area type selection signal (Y03)
ON
or OFF.
The basic configuration of the area is the same whether the fixed type
or ring type is selected: as shown in the figure below,
it
stores a total
of a items of fault information, each comprising an error code, de-
tailed data length, and detailed data.
In the case of the ring type, the items are always stored in other, with
the latest fault information at the head.
In the case of the fixed type, when
8
items have been stored, items 2
through
8
are fixed and the next time a fault occurs only the head item
changes.
In the case of both types, then the communication fault area clear re-
quest signal (Y02) comes
ON,
all fault information is cleared.
When the communication fault detection signal reset signal (YO1)
comes
ON,
the communication fault detection (XO1) goes OFF, but
the contents of the communication fault area are retained.
The configuration of the communication fault area shown below.
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