Switching Time For Duplex Units - Omron SYSMAC CS1W-CLK13 Operation Manual

Switching Time for Duplex Units

8-5 Switching Time for Duplex Units
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• It is also possible to use only some of the Units in the Controller Link Net-
work in duplex operation. In this case, up to a total of 62 active and
standby Controller Link Units and Controller Link Units that are not used
in duplex operation can be connected. The Units that are not used in
duplex operation can include both existing Units (CS1W-CLK12, CS1W-
CLK52, CVM1-CLK12, or CVM1-CLK52) and duplex-compatible Units.
Only some Controller Link Units
are used in duplex operation.
(CS1D CPU Unit used.)
• As long as they are mounted on the same PLC, two Controller Link Units
used in duplex operation can be mounted on different Racks or in non-
adjacent slots.
• When using Units in duplex operation, construct the Controller Link Net-
work so that the Controller Link Units used in duplex operation are adja-
cent to each other in the network. (As long as they are within the
maximum distance between nodes for Controller Link Networks, there is
no restriction on the physical distance.) If they are not adjacent to each
other, because the node position will change when there is an active/
standby switchover, it may not be possible to identify the location of dis-
connections.
• Communications data passes through Controller Link Units in standby
mode in both directions without any processing. If the backup power sup-
ply for a Controller Link Unit in standby mode is interrupted, however, a
disconnection may be detected at the position of the Unit.
• In CS1D Systems with Controller Link Units used in duplex operation, set
the duplex node as a startup node for data links (Data Link Start/Stop Bit
in the CS1D System CPU Unit is turned ON). If the duplex node is not set
to be a startup node for data links (Data Link Start/Stop Bit in the CS1D
System CPU Unit is OFF), and the relevant node is operating as a polling
node, the network's data links may stop if an ACT/STB (active/standby)
switchover error occurs.
If an error occurs in an active Controller Link Unit and there is an active/
standby switchover, or if an active Controller Link Unit is replaced online,
because the relevant node will temporarily leave and then re-enter the net-
work, communications operations (both message communications and data
links) will be temporarily stopped.
The time required for communications to resume can be obtained using the
following equation.
Equation for Calculating the Communications Recovery Time for Duplex
Units
Maximum communications recovery time = 1,000 ms + Network participation
waiting time (See note.) + PLC cycle time × 2
Minimum communications recovery time = 1,000 ms
Controller Link Units are not used in
duplex operation.
(CPU Unit does not have to be CS1D.)
Section 8-5
Controller Link Units
that are either active
or not used in duplex
operation
Standby Controller
Link Units