Confirming Normal Slave Unit Operation In Communications Modes 0 To 3 - Omron GQ-CRM21 Operation Manual

4-1-2 Confirming Normal Slave Unit Operation in Communications Modes 0 to 3

Participation Flags and Communications Error Flags
• To check whether Slave Units are normally participating in the network, the Participation Flags and
Communications Error Flags in the Status Area are used.
• Participation Flags:
A Participation Flag turns ON once the corresponding Slave Unit starts participating in the net-
work after the system is started (i.e., when the power is turned ON). It remains ON even if the
Slave Unit stops participating due to a communications error.
4
• Communications Error Flags:
A Communications Error Flag turns ON if the applicable Slave Unit cannot communicate with the
Master Unit for any reason after the Slave Unit has joined the network (i.e., if the Participation Flag
is ON). It turns OFF when the error is removed.
Therefore, in the ladder program, the applicable Slave Unit has stopped participating when both the
Participation Flag and the Communications Error Flag are ON. Similarly, the applicable Slave Unit is
operating normally when the Participation Flag is ON and the Communications Error Flag is OFF.
Example: This example shows executing I/O with the applicable Slave Unit when the Participation Flag and
Communications Error Flag are combined and taken as a condition to confirm that operation is normal.
• The operation of the Participation Flags and Communications Error Flags depends on the status of
pin 4 (REGS) on the CompoNet DIP switch on the front of the Gateway Unit.
Pin 4 (REGS) of CompoNet DIP switch on front of
Gateway Unit
OFF (Registration table disabled.)
ON (Registration table enabled.)
4 - 3
Slave Unit A
Participation Flag
Slave Unit A
Communications
Error Flag
A communications
error occurs at
Slave Unit A.
Partici-
pating
Participation
Flag
A
Normal
operation
a
The Slave Unit stops participat-
ing, but the Participation Flag
remains ON.
The cause of the communi-
cations error is removed.
(Slave Unit A is automati-
cally restored to the
Not
network.)
partici-
pating
Participating
Communica-
tions Error
Normal operation
Flag
a
B
Allocated I/O
address
Input processing from
applicable Slave Unit
Applicable Participation Flags and
Communications Error Flags
Flags for all Slave Units
Only flags for registered Slave Units.
Participation Flags and Communications Error Flags
for unregistered Slave Units will not operate.
CompoNet Gateway Unit for CC-Link Operation Manual