11
2800 Laura Lane • Middleton, WI 53562
|
800.288.9383
|
www.tcsbasys.com
Building Automation Systems
11
Installation
Use 22 AWG, twisted shielded two-conductor or three-conductor cable for network wiring. Network wiring should start
at one controller and go to the next and then go to the next, until the final controller is reached. Wiring is such that all “A”
wires are connected to “A” wires, all “B” wires are connected to “B” wires, and all “REF” wires are connected to “REF” wires.
NOTE:
“A” refers to the negative (–) RS485 connection and “B” refers to the positive (+) RS485 connection.
A 120 Ω terminating resistor should be placed at each of the two ends of the network directly across the “A” and “B” wires.
•
If the Panel will be at one end of the network, hard-wire a 120 Ω terminating resistor across the “A” and “B” terminals of
the QWL2040 Panel (See
Three-Wire Network Wiring on page 11
).
• If the Panel will be in the middle of the network, do not wire in the terminating resistor on the QWL2040 Panel terminal
block
Connect one end (ideally the furthest end from the QWL2040 Panel) of the shield wire of the network wiring to earth
ground.
NOTE:
If you encounter time-out errors, contact TCS Technical Support (800.288.9383, ext. 2).
Three-Wire Network Wiring
Follow this wiring diagram for all three-wire systems (this is common).
NOTES:
In the middle of the network, all network wiring shields should be twisted together and taped off to prevent
accidental grounding. More than one ground on the network wiring can result in communication failure.
A maximum of two terminating resistors can be used.
QWL2040 Panel at end of the
network.
QWL2040 Panel in the middle of the
network.
3
2
Shielded, twisted three-conductor
communications wiring with one end
earth grounded. (120 Ω balancing
resistors provided.)
Shielded, twisted three-conductor
communications wiring with one end
earth grounded. (120
Ω
balancing
resistors provided.)
4
NOTES:
1. If using more than 64 controllers,
use the second RS485 port or
additional QD1010 adapters.
2. Each controller must use the
same baud rate and be assigned
a unique address.
1
A
B
REF
Shield
A
B
REF
A
B
REF
Earth Ground
Only at one end
Drain
Wire
Last in Daisy Chain
120Ω
Terminating
Resistor
COM 1
REF
A
B
Drain
Wire
120Ω
Terminating
Resistor
A
B
REF
A
B
REF
A
B
REF
Last in Daisy Chain
Shield
Last in Daisy Chain
Earth Ground
Only at one end
120Ω
Terminating
Resistor
A
B
REF
A
B
REF
A
B
REF
Shield
Drain
Wire
COM 1
REF
REF
A
A
B
B
120Ω
Terminating
Resistor
1
2
3
3
4
4
4
COM 1
REF
A
B
COM 1
REF
A
B