9·65
03
(8)
Remove the connector on point
A, and turn ON the termination
resistance of the master station.
07
(8)
06
(8)
05
(8)
Master
station
04
(8)
B
D
7
OFF
A C
Disconnection
• If the bus cable between the slave station 05
(8)
and 06
(8)
is disconnected in the following system.
State of an individual communication flag
D
01
(8)
02
(8)
D
0
OFF
6 5
Unstable
1234
D
7
D
0
OFF
6 5
ON
1234
D
7
D
06 5 1234
As the communication possible stations
03
(8)
, 02
(8)
, 01
(8)
, and 04
(8)
are normal, the
state of communication monitoring flag is
as follows.
Connect the A connector, and
then remove the connector on
point B.
D
7
D
0
OFF
6 5
OFF ON
Unstable
OFF OFF ON
Unstable
CountermeasureCause
Disconnection in the bus cable and the
branch cable between the station 05
(8)
and
06
(8)
, or contact failure of the connectors
Error on the slave station 06
(8)
Remove both the bus cable and
the branch cable connectors. After
that, shorten one of these
connectors and check conductivity
using a tester.
Exchange the slave module.
OFF
1234
As the one side of the termination
resistance is lost, all of the
communication possible stations 05
(8)
,
06
(8)
, and 07
(8)
are abnormal, and the
station 05
(8)
is unstable.
Remove the connector on point
C and make sure the B
connector is not connected.
Turn ON the termination
resistance of the slave module
05
(8)
.
D
7
D
06 5
OFFON ON
1234
As the communication possible station
05
(8)
is normal, abnormal points exists
ahead of the point C.
Connect the C connector and
make sure the B connector is
not connected, and remove the
connector at the next point to
the point D.
Turn OFF the termination
resistance of the slave station
05
(8)
, and turn ON the
termination resistance of the
end station 06
(8)
.
As the one side of the termination
resistance is lost, the station 05
(8)
and
06
(8)
become communication possible
stations, but the station 05
(8)
is unstable
and the station 06
(8)
is turned to OFF, so
the abnormal states occur between the
point C and the point D.