Omron CS1W-CLK12-V1, Operation Manual

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Switching Time for Duplex Units Section 8-5
• 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.
8-5 Switching Time for Duplex Units
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
Note Network Participation Waiting Time:
Maximum network participation waiting time = Communications cycle time
×
(Maximum node address in the network parameters
−
1)
÷
Number of polled
nodes in the network parameters
Calculation Example
As an example, the calculation for the following conditions is given below.
Communications cycle time: 20 ms (Number of nodes: 10; Number of data
link words: 1,000)
Network parameters: Default settings (Maximum node address: 62;
Number of polled nodes: 4; Number of event-
frames: 35)
PLC cycle time: 15 ms
The communications recovery time is given by the following calculation:
Maximum value = 1,000 ms + 20 ms
×
(62
−
1)
÷
4 + 15 ms
×
2 = 1,335 ms
Minimum value = 1,000 ms
Note The maximum network participation waiting time can be reduced by changing
the network parameters in the way described below. Making settings 1 and 2
below will reduce the network participation waiting time to a maximum of 1
communications cycle. Change the network parameters using CX-Net in CX-
Programmer.
1. Set the maximum node address setting in the network parameters to the
same value as the maximum address of the actual nodes in the network.