Mitsubishi MELSEC-A Series Operating Manual page 144

6. HOW TO USE EACH FUNCTION
MELSEGA
2) The state of the positive loop line (F loop) or the reverse loop line
(R loop) of the self is displayed.
(The contents of the special relay for link M9241 and M9242 are
displayed.)
OK: When the line is normal
NG: When the line is abnormal
3)
It
displays whether or not loopback is executed in the self.
(The contents of the special relay for link M9243 are displayed.)
EXECUTED: When executing a loopback in the self
NOT EXE. : When not executing a loopback in the self
4) It displays whether or not data of link relay (B), link register (W),
or link output (Y) could be received from the master station.
(The contents of the special relay for link D9246 are displayed.)
RECEIVED : When receiving
B,
W, or
Y
of a master station by
using cyclic communications
NOT RCV : When the self cannot receive
B,
W, and Y of a
master station because of disconnection.
5)
It
displays whether or not the link relay (B) and link register (W)
can be received from the master station of a higher loop.
(The contents of the special relay for link D9247 are displayed.)
RECEIVED :When receiving
B,
W, and
Y
of a master station
using cyclic communications
NOT RCV : When B and W of the master station of a tier-2
system cannot be received, or when turning ON
M9208
6) The operating state of other local stations is displayed by the
following messages:
(The contents of the special registers for link 09248 to D9255 are
displayed.)
RUN : When the ACPU is in the RUN state.
STOP
: When the ACPU is in the STOP or PAUSE state.
DOWN :When it goes into the disconnected state by the
When the monitoring station is a remote I/O station, the dis-
play remains "RUN".
power supply going OFF.
(5) When connected to a remote I/O station, the loop state, I/O allocation
state, and error codes can be displayed.
(a)Loop state display (b)
I/O
allocation state and an error code
displays
P LO0P:OK
LOOP BK
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