OPERATION MANUAL CompoBus/S

CJ1W-SRM21 Master Unit for CJ-series PLCs Section 4-3
120
1 (ON): Communications participation
The flag won’t change even if the node is withdrawn from the system.
Output Slave Error Flags
These flags indicate the communications status of the Output Slaves (0 to
15). All of these flags are reset when the power is turned ON or operation
is restarted.
0 (OFF): Communications normal or inactive node
1 (ON): Withdrawn from communications (communications error)
Input Slave Error Flags
These flags indicate the communications status of the Input Slaves (0 to
15). All of these flags are reset when the power is turned ON or operation
is restarted.
0 (OFF): Communications normal or inactive node
1 (ON): Withdrawn from communications (communications error)
Note 1. When the CompoBus/S System starts up, inputs from Input Slaves and
outputs to Output Slaves become effective when the Active Slave Flag for
the Slave is turned ON. It is recommended to write a ladder program that
verifies that the Slave’s Active Slave Flag is ON and its Error Flag is OFF
before transmitting or receiving I/O data.
2. When CJ-series Master Units are set to communications stop mode, communications
will stop when the Output Slave Error Flag or Input Slave Error
Flag will turn ON. (Refer to 4-3-5 Slave Registration Function and Communications
Stop Mode.)
4-3-5 Slave Registration Function and Communications Stop Mode
The CJ-series Master Units now support a Slave registration function and
communications stop mode. This new capability enables the CompoBus/S
System to deliver increased reliability.
Slave Registration Function
The words allocated in the DM Area to the Master Unit as a Special I/O Unit
contains a Slave registration table. By registering the Slaves that are normally
participating in communications, the Slaves that are not joined to the network
or are slow to join, or unregistered Slaves that are illegally joined can be monitored.
This function prevents system malfunctions due to incorrect wiring on site.
The Slave registration function is enabled by turning ON pin 4 of the DIP
switch on the Master Unit.
Communications Stop Mode
By setting communications stop mode, remote I/O communications will stop
when a communications error occurs, and information on the Slave with the
communications error is stored in the Special I/O Unit DM Area.
This function prevents the System from running on incorrect I/O data without
having to disconnect a Slave with a communications error, and enables quick
troubleshooting of the communications error.
When remote I/O communications are stopped in communications stop mode,
they will not resume when the cause of the error is removed. To restart remote
I/O communications, turn ON the power again, or restart the Unit. When the
Unit is set to standard communications mode, even if a communications error
occurs, the remote I/O communications will continue with the Slave with the
error disconnected. Also, the Slave with the communications error is not