2800 Laura Lane • Madison, WI 53562 | 800.288.9383 • fax: 608.836.9044 | www.tcsbasys.com
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All controls connected to the network will need to be programmed with the same communication baud rate as well as
a unique communication address from 0 to 255, excluding 248 . On controllers with displays, this can either be done
from the face of the controller using the keypad and display, or using TCS Insight software, or by calling TCS Technical
Support . TCS Technical Support can access the QD2040b online and change the address of a controller .
Use 22 AWG, twisted shielded 3-conductor cable for network wiring . Network wiring should start at one controller and
go to the next and then go to the next, and so on 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 .
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 QD2040b will be at one end of the network, hard wired a 120 Ω terminating resistor across the “A” and “B”
terminals at the QD2040b (See 1 below) .
If the QD2040b will be in the middle of the network, do not wire in the terminating resistor on the QD2040b terminal
block (See 2 below) . Finally, connect one end (ideally the furthest end from the QD2040b) of the shield wire of the
network wiring to earth ground . TCS recommends a 250 milliseconds time out period for all wired networks, and 1000
milliseconds for wireless networks . If you encounter timeout errors please contact tech support .
NOTE:
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 .
NOTE:
A maximum of 2 terminating resistors can be used . See Figure below .
NETWORK
WIRING & SETUP
RS485 Controller Network Wiring and Setup
A
B
REF
Shield
A
B
REF
A
B
REF
Earth Ground
Only at one end
Drain
Wire
Last in Daisy Chain
120
Ω
Terminating
Resistor
...
COM 1
COM 2
REF
REF
A
A
B
B
USB PORT 2
USB PORT 1
ETHERNET
USB PORT 3
USB PORT 4
VIDEO
AUX VIDEO
Drain
Wire
...
120
Ω
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
120
Ω
Terminating
Resistor
A
B
REF
A
B
REF
A
B
REF
Shield
Drain
Wire
COM 1
COM 2
REF
REF
A
A
B
B
USB PORT 2
USB PORT 1
ETHERNET
USB PORT 3
USB PORT 4
VIDEO
AUX VIDEO
120
Ω
Terminating
Resistor
1
2
3
3
4
4
4
1
3
2
4
QD2040b in the middle of the network
Shielded, twisted 3-conductor communications wiring
with one end earth grounded. (120
Ω
balancing
resistors provided.)
Shielded, twisted
3-conductor
communications wiring
with one end earth
grounded. (120
Ω
balancing resistors
provided.)
NOTES:
1 .
If using more than 64
controllers, use the second
RS-485 port or additional
QD1010 adapters.
2 .
Each controller must use
the same baud rate and be
assigned a unique address.
QD2040b in the end of the network
