Mitsubishi MELSEC-A Series Reference Manual page 269

9. PROGRAMMING
Device
Name
Number
D9224
Initial
communication
between local
stations/remote I/O
stations
D9225
D9228
Local station/
remote I/O station
error
D9229
Receive error
D9240
detection count
Table 9.6 List of MELSECNET/B special link registers (Continued)
Data
Stores the status of
No.1 to No.16
Stores the status of
No.17 to No.31
Stores the status of
No.1 to No.16
Stores the status of
No.17 to No.31
Stores the total number of
receive errors
• Stores station Nos. of local stations or remote I/O stations
communicating initial setting data for data link processing into the
corresponding bits in D9224 to D9227 as shown below.
• When a local stations/remote I/O stations is communicating initial
setting data (link parameters), the bit corresponding to the station
number is set.
Example: When No. 23 is communicating initial setting data (link
parameters), 1 is set to bit 6 of D9225.
When D9225 is monitored, its value is 64 (40
• When the initial setting data has been communicated, the bit is
automatically reset to "0".
• Stores the number of the local stations/remote I/O stations in the
data link that is determined by a master station to be faulty.
• A station is determined to be faulty if the data returned from it to
the master station is not received within the specified length of
time.
• When data is not received within the specified length of time, the
bit corresponding to the station number of the local station/
remote I/O station is set.
Example: When an error at No. 3 causes it to fail to return the data
to the master station, "1" is set for bit 2 of D9228.
When D9228 is monitored, its value is "4".
• When the loop line becomes faulty, "1" is set for the bits of the
stations after the fault or for all local stations/remote I/O stations.
• When the master station becomes faulty or the setting for the
monitoring time is too small, "1" is set for the bits corresponding
to all local stations/remote I/O stations.
• When the faulty station returns to nomal, the bit is automatically
reset to "0".
• Stores the number of times that the following errors are detected
in the loop line currently being used:
"CRC", "AB.IF", "OVER"
• Counting stops if the number of receive error occurrences
exceeds the maximum limit "FFFF
• Execute the reset operation to clear the data to "0".
9 - 23
Description
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