31
Supplying Power to the Slaves
Section 2-3
2-2-3
Terminator Connection
System with Distinction
between Main and Branch
Lines
A terminator must be connected to the end of the main line opposite the Mas-
ter (the farthest end of the cable) in order to stabilize communications. When
the last Slave in the system is connected to the main line by a T-branch con-
nector, make sure that the terminator is farther from that T-connection than
the Slave so that the terminator is farther from the Master.
The following diagram shows the connections in a typical CompoBus/S Sys-
tem with distinguished main and branch lines. The power supply system has
been omitted.
System with No
Distinction between Main
and Branch Lines
A terminator must be connected to the end of the communications cable far-
thest from the Master in order to stabilize communications. When the last
Slave in the system is connected to the communications cable by a T-branch
connector, extend the cable to connect the terminator or connect the termina-
tor at the T-branching position. The cable distance to the terminator includes
the total cable length.
2-3
Supplying Power to the Slaves
The Slaves must be supplied with power for communications and some
Slaves must have a separate power supply for I/O. The methods for supplying
power to the Slaves depend on the type of communications cable being used.
Master
Slave
Slave
Slave
Slave
Slave
Slave
Terminator
Main line
Branch line
T: T-branch connection
M: Multidrop connection
Slave
Slave
Slave
Slave
Branches can't
be made from
branch lines.
Branch line L
2
≤
3 m
L
1
> L
2
Slave
Slave power
supply
Usage
2-conductor VCTF
cable
4-conductor VCTF
cable
Special Flat Cable
Network
power supply
1
For both commu-
nications and I/O
External power sup-
ply (collective supply
possible)
Power supplied via 4-
conductor VCTF
cable, Special Flat
Cable, or from exter-
nal power source
Multiple power
supply
2
For communica-
tions
External power sup-
ply (collective supply
possible)
Power supplied via 4-
conductor VCTF
cable, Special Flat
Cable, or from exter-
nal power source
For I/O
External power sup-
ply (collective supply
impossible)
External power
source
Local power
supply
1
For both commu-
nications and I/O
External power sup-
ply (collective supply
impossible)
External power
source