(Theoretical) - Omron C200HW-CLK21 Operation Manual

Changing the Data Link Tables with Active Data Links
Data link area of node with the data link table
to be changed
Data link send data
Data link receive data
10-2-4 Timing Required to Change Data Link Tables with Active Data
Links (Theoretical)
Note
Command re-
ceived to change
with active data
links
Most recent data read from
Unit
Most recent data received
from other node
Refresh stopped
Data link communications will continue, so the Communications Error Flag for
the data link status will not turn ON in any of the nodes in the network.
Refer to 10-2-4 Timing Required to Change Data Link Tables with Active Data
Links (Theoretical) for details on timing required to change the data link
tables.
When changing data link tables with active data links, the data refresh for the
corresponding node will stop temporarily. During that time, even if the data in
the data link send area in the PLC is refreshed, it will not be sent as data link
data to other nodes. Data received from other nodes will also not be shown in
the data link receive area of nodes with data link tables that are being
changed. The data refresh interrupt timing (maximum theoretical value) is as
follows:
Data link refresh maximum interrupt time = 2
with data link table being changed (See note 1.) + 3
time (ms)
1. When CS- or CJ-series PLCs are being used, if the total number of data
link send words exceeds 7,800 words, this value is multiplied by 3.
2. Consider the effect of the data link refresh interrupt time on the applica-
tions when changing the data link tables. If the maximum interrupt time is
not suitable for the user application, transfer the data link table after stop-
ping the data links from a Programming Device as before, and then restart
the data links.
Change during
active data links
completed
Data immediately Most recent data read from
Unit.
before change
Data immediately Most recent data received from
before change other node
Refresh resumed
Section 10-2
Time
Unit cycle time of the node
communications cycle
337