Limitations Of Communications Cable Power Supply - Omron C200HW-SRM21-V1 - 08-2007 Operation Manual

Supplying Power to the Slaves
2-3-3

Limitations of Communications Cable Power Supply

2. If multiple CompoBus/S Systems are used, provide a separate communi-
cations power supply for each CompoBus/S System to prevent unstable
operation due to unwanted noise paths in the power supplies of the Com-
poBus/S Systems.
Master
CompoBus/S
System 1
Communications
power supply (See note.)
Master
CompoBus/S
System 2
Communications
power supply (See note.)
Note: Use a separate communications power supply for each line.
3. When using CJ-series Master Units, use 6-pin communications connec-
tors that allow simultaneous connection of communications and power
supply cables. Power can be supplied to the Slaves easily by connecting
the communications power supply to the Master Unit without preparing the
communications cables, as shown in the following diagram.
CJ-series
Master Unit
Communications
Power
supply
Power
supply
The BS+ and BS terminals of the CJ-series Master Unit's communica-
–
tions connector are connected internally. (The Master Unit does not use
the BS+ or BS terminals.)
–
Check the following points when using 4-conductor VCTF or Special Flat
Cable to supply power to Slaves.
• The 4-conductor VCTF or Special Flat Cable's allowable current
• The Extension Connector's allowable current
(when using an Extension Connector)
• The allowable current of the CJ-series Master Unit's communications con-
nector (when using CJ-series Master Units)
• Cable length limit due to voltage drop
1. 4-conductor VCTF or Special Flat Cable's Allowable Current
The allowable current through the 4-conductor VCTF or Special Flat Cable
depends on the ambient temperature, as shown in the following tables.
Main line
Slave Slave
Main line
Slave
Slave
+
BS+
BDH
H
BDL
L
−
BS−
+
BS+
−
BS−
+
−
Section 2-3
Special Flat Cable or
4-conductor VCTF
cable (Wiring Special
Flat Cable is easy as
it is connected to the
communications
connector in the
same order.)
35