33
Supplying Power to the Slaves
Section 2-3
2-3-1
Using 2-conductor VCTF Cable
Power cannot be supplied to the Slaves through 2-conductor VCTF cable.
When a CompoBus/S System is being constructed with 2-conductor VCTF
cable, each Slave must be supplied with power along a route separated from
the VCTF cable. Furthermore, an I/O power supply must be provided for
Slaves that require an I/O power supply.
Independent Power Supplies
Note
Both T-branch connections and multidrop connections are possible with each
type of power supply.
Common Power Supply
When using a common power supply with long power lines, make sure that
there isn’t a significant decline in the supply voltage due to attenuation.
Note
Both T-branch connections and multidrop connections are possible with each
type of power supply.
It is possible to supply all communications power collectively via a single line.
If the power supply line is too long, however, the conductor resistance of the
cable will cause voltage to drop. For information concerning the allowable
length of the collective power supply cable, refer to
Master
H L
+ –
H L
+
–
H L
H L
H
L
Termi-
nator
Slave
Slave
Slave
Slave
Power
supply
2-conductor VCTF cable
Multidrop (See note.)
Branch line
(See note.)
Common power supply for
communications and I/O
Communications
power supply
I/O power
supply
+ –
+ –
+ –
+
–
+ –
+ –
+ –
+ –
+ –
+ –
Communications
power supply
Network power supply
Power
supply
Power
supply
Power
supply
Power
supply
Power
supply
Multiple power supplies
Local power supply
I/O power
supply
Common power supply for
communications and I/O
Branch line
For I/O
For I/O
Branch line
For
Communications
For Com-
munications
Master
H L
+ –
H L
+
–
H L
H L
H
L
Termi-
nator
Slave
Slave
Slave
Slave
Power
supply
2-conductor VCTF cable
Multidrop (See note.)
Branch line
(See note.)
Common power supply for
communications and I/O
+ –
+ –
+
–
+ –
+ –
+ –
+ –
+ –
I/O power supply
Network power supply
Power
supply
Power
supply
Power
supply
Multiple power supplies
Local power supply
Common power supply for
communications and I/O
Note that voltage will
drop if the power supply
line is too long.
For I/O
Branch line
Branch line
For Communications
For I/O
For Communications
I/O power supply