2-4
Section
Backup Power Supply Wiring (Optical Ring Systems Only)
38
2-4
Backup Power Supply Wiring (Optical Ring Systems Only)
A node bypass function can be used with an Optical Ring Controller Link System
(either H-PCF cable or GI cable) by supplying a backup power supply to the
Units and Boards. This will prevent the entire network from going down if a node
malfunctions or the power supply to the PC or computer is turned OFF.
Optical transmission path
Bypass
Power supply
down
Computer
24 VDC
backup power supply
Each node requires a backup power supply for the node bypass function. Sever-
al nodes can be connected to a single power supply or each node can be con-
nected to an independent power supply. If several nodes are connected to a
single power supply, be sure to wire each node separately as shown in the dia-
gram.
2-4-1 Backup Power Supply Specifications
The input specifications for the backup power supply to the Controller Link Unit
and Support Board are described below. When providing a backup power sup-
ply, make sure that the following specifications are satisfied.
Item
Specifications
Power supply voltage
24 VDC
Allowable power supply
voltage fluctuation range
20.4 to 26.4 VDC (24 VDC, –15 to +10%)
Consumption current
24 VDC, 400 mA max. (per node)
Inrush current
2.5 A max. (when 24-VDC rising time is 5 ms)
An OMRON S82K-series Power Supply Unit is recommended.
Note
1. If connecting multiple nodes to one power supply, or if the distance between
the power supply and the node is great, carefully consider the maximum cur-
rent and voltage to satisfy the specifications described above using the
node power supply connectors and terminal positions.
2. Power supply from the backup power supply is given priority. Consider the
following points when designing a system.
a) Turn ON the backup power supply before turning ON the power supply to
the PC and computer.
b) The communications data will be corrupted in the instant when the back-
up power supply is turned ON or OFF.
c) To make sure that the node bypass function is operating when the power
supply to the PC or computer is OFF, use a separate backup power sup-
ply that is not connected to the PC or computer.
d) Always use a separate backup power supply. Do not use the same sup-
ply as the I/O power supply, motor power cables, or control power cables.
e) Use a backup power supply with double or reinforced insulation.
3. Use the correct power supply voltage, as given above.
