4. FUNCTIONS
MELSEC-A
4-3
(2)
Service FREEZE, UNFREEZE
(Group 8)
Slave 1
(Group 3)
Slave 2
(Group 3)
Slave 3
(Group 3)
Slave n
Master
(FREEZE transmission to group 3)
Input data
FREEZE
Input image memory: The data is always refreshed by polling.
<during FREEZE cancel/default>The actual input is input to the input memory unchanged
(normal condition)
<during FREEZE execute>The actual input is input once into the input image memory at the FREEZE
service timing.
Service FREEZE (issued within the same group)
(3)
Group selection
•
The number of groups is from 1 to 8 if with a total of 8 groups.
•
The slave can exist in arbitrary group of the 8 groups. They can also exist in multiple groups.
(The configurator specifies in which group which slaves exist.)
•
Multiple groups can be arbitrarily selected from the sequence program and global control
executed.
•
When selecting group 0 and transmitting the service is transmitted to all slave stations.
Master
(transmitted to
groups 1 and 2)
PROFIBUS-DP network
Slave
Group 1
Group 5
Group 2
Group 8