In the case of a master station (PC 00)·Communication monitor flag

This flag is used to monitor the communication condition with other stations. Non-connected station keeps this flag as “OFF.”

Flag

Condition for flag operation

Flag operation

Own

When the link start switch is set to “01(H),” and the master station is operating

ON

station

normally.

flag

 

 

When the link start switch is set to “00(H).”

 

(master

OFF

Improper setting of parameter, BCC check error, or other errors.

station)

 

Flag

Condition for flag operation

Flag operation

 

 

 

 

Other

Normal communication with slave stations.

ON

Specific

 

 

slave

Stopped communication or unable to

 

station’s

 

flag

communicate with slave stations.

OFF

station

Communication monitor flag (1) of the master

 

(01 to 77)

All slave stations

 

 

station is turned “OFF.”

 

 

 

 

The master station periodically executes communication recovery operation with the communication error slave station. When the error situation is recovered, the master station returns to normal communication.

·Operation condition monitor flag [1]

This flag is used to monitor the operation condition of slave stations when the communication with each slave station is normal.

Non-connected station keeps this flag as “OFF.”

 

 

Flag

Condition for flag operation

Flag operation

9

 

 

 

 

 

Own

Communication monitor flag (1) of the master station is turned “ON.”

ON

 

station flag

 

 

(master

Communication monitor flag (1) of the master station is turned “OFF.”

OFF

 

 

station)

 

 

Flag

Condition for flag operation

Flag operation

 

Slave station is operating.

ON

Specific

 

 

 

slave

Other

Slave station stops operation (not by an error cause).

 

station’s

 

OFF

station

Communication monitor flag (1) of the master

All slave stations

flag

station is turned “OFF.”

 

(01 to 77)

 

 

 

Slave station that communication monitor flag (1)

Not specified

 

is turned to “OFF.”

 

 

 

Even if a master station PC has stopped operation normally or by an error, the JW-20CM turns “ON” this flag while communicating.

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