
4. FUNCTIONS
MELSEC-A
4-15
(5)
Communication trouble area
When some kind of trouble occurs during communication the AJ71PB92D/A1SJ71PB92D stores
the contents of the trouble in this area. Fixed type or ring type can be selected for this area by
turning the communication trouble area type selection (Y03) on or off (refer to Section 4.2.2 (9)).
As shown in the following diagram, a total of 8 pieces of trouble information that consist of the
trouble code, detailed data length, and detailed data can be stored in the basic configuration
regardless of whether for fixed or ring data.
Ring type data is stored in order from the header with the header always being the latest trouble
information.
With fixed type data, when 8 pieces of trouble information are stored the areas 2 to 8 (data 1 to 7)
are fixed, so when the next new trouble occurs only header area 1 (data 8) is updated.
All trouble information for either type can be cleared by turning on the communication trouble
area clear request signal (Y02). When the communication trouble detection signal reset signal
(Y01) is on, the contents of the communication trouble area are held though the communication
trouble detection signal (X01) turns off.
The communication trouble area is configured as shown below.
(a)
Communication trouble area configuration
Address
2040/7F8h
2044/7FCh
2045/7FDh
2049/801h
2050/802h
2054/806h
2075/81Bh
2079/81Fh
Trouble information area 1
Trouble information area 2
Trouble information area 3
Trouble information area 8
2040/7F8h
2041/7F9h
2042/7FAh
2043/7FBh
2044/7FCh
Error code (refer to the next page.)
Detailed data length (0 to 3)
Detailed data 1
Detailed data 2
Detailed data 3
Data 1
Ring
ty
p
e
Fixed type
Trouble
information area 1
Trouble
information area 2
Trouble
information area 1
Trouble
information area 2
Trouble
information area 8
Trouble
information area 8
Data 2
Data 9
Data 8
Data 1
Data 2
Data 1
Data 1
Data 7
Data 1
Data 8
Data 7
Data 1
Data 8
Data 2
Data 9
Data 7
Data 1
Address