40
Supplying Power to the Slaves
Section 2-3
1,2,3...
1.
Supplying I/O Power for Slaves from Multiple Power Supplies
Supplying I/O power from several sources rather than from a single source
enables line current to be reduced, and reduces voltage drops.
2.
Supplying Power from Single Unit
Use the following methods for keeping voltage drops within allowable
range when power is supplied from a single source.
• Increase cable thickness.
• Raise output voltage of power supply slightly.
• Shorten wiring distances.
3.
Considerations Relating to Power Supply Malfunctions
It is necessary to examine system operation in the event of a power supply
malfunction.
Example:
a) Design the system to halt operation of all loads in the event of a single
power supply failure.
b) Design the system to prevent all loads stopping operation by installing
more than one power supply.
4.
Cost Considerations
It is also necessary to examine the costs associated with I/O power supply
installation, such as the number of power supplies, cable thickness, cable
length, and the labor required.
CP
CP
. . .
. . .
Power supply
(24 V DC)
Slave
Slave
Slave
Slave
Power supply
(24 V DC)