Mitsubishi MELSEC-A series Programming Manual

APP - 36
APPENDICES
Table 1.5 Link special Register (Continue)
Number Name Description Details
D9204
(Continue)
Link status
• Loopback in forward loop only
• Loopback in reverse loop only
D9205
Loopback executing
station
Station executing forward
loopback
Stores the local or remote I/O station number at which loopback is
being executed.
In the above example, 1 is stored into D9205 and 3 into D9206. If
data link returns to normal status (data link in forward loop), values in
D9205 and D9206 remain 1 and 3. Reset using sequence program
or the RESET key.
D9206
Loopack executing
station
Station executing reverse
loopback
D9207 Link scan time Maximum value
Stores the data link processing time with all local and remote I/O
stations.
• Input (X) , output (Y) , link relay (B) , and link register (W) assigned
in link parameters communicate with the corresponding stations
every link scan.
• Link scan is a period of time during which data link is executed with
all connected slave stations, independently of the sequence
program scan time.
D9208 Link scan time Minimum value
D9209 Link scan time Present value
D9210 Retry count Total number stored
Stores the number of retry times due to transmission error.
Count stops at maximum of "FFFF
H" .
RESET to return the count to 0.
D9211 Loop switching count Total number stored
Stores the number of times the loop line has been switched to
reverse loop or loopback.
Count stops at maximum of "FFFF
H".
RESET to return the count to 0.
Master
station
Station 1 Station 2 Station n
Forward loopback
Station 3
Master
station
Station 1 Station 2 Station n
Reverse loo
p
back
Station 3
Master
station
Station 1 Station 2 Station n
Forward loop Reverse loop
Station 3

Mitsubishi MELSEC-A series Specifications

General

Brand	Mitsubishi
Model	MELSEC-A series
Category	Controller
Language	English