Precautions For Duplex Systems - Omron SYSMAC CS1W-CLK13 Operation Manual

Precautions for Duplex Systems

Note
8-4 Precautions for Duplex Systems
210
5. When the settings are completed, the I/O Table Window will be displayed
in the way shown below. The first word in the CPU Bus Unit Area allocated
to the active Unit (1500 in the example below) is displayed in brackets.
(The first word allocated in the CPU Bus Unit Area depends on the unit
number setting.) For the standby Unit, "STB" is displayed in brackets.
1. Duplex settings for Communications Units (i.e., PLC Setup settings and I/
O table creation/editing) can be performed with CX-Programmer Ver. 3.0
or later.
2. When settings are made for a standby Unit, the following message is dis-
played. If the duplex settings for Communications Units in the PLC Setup
are complete, this message can be ignored.
• 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
network, communications operations (both message communications and
data links) will be temporarily stopped. At this time, the Data Link Partici-
pation Flag for the relevant node will turn OFF, and the Communications
Error Flag will turn ON. After the switchover, communications will resume
and the status will return to normal (the Data Link Participation Flag turns
ON and the Communications Error Flag turns OFF). For this reason, per-
form the following processing in systems where there are duplex nodes in
the network.
• When using message communications, set the number of retries for
the SEND, RECV, and CMND instructions (i.e., set the number of re-
tries in the control data to a value other than 0), and be sure to perform
resend processing for instructions.
Section 8-4
For the active Unit, the first
allocated word is displayed.
For the standby Unit,
"STB" is displayed.