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7
WIRING
QD2040c RS485 Connections Diagram II
1
3
2
4
QD2040c in the middle of the network
Shielded, twisted 3-conductor communications wiring
with one end earth grounded. (120
Ω
balancing
resistors provided.)
Can be used with up to
a total of 64 controllers.
If more controllers are
required, add another
QD2040c.
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.
QD2040c in the end of the network
A
B
Shield
A
B
A
B
Earth Ground
Only at one end
Drain
Wire
Last in Daisy Chain
120Ω
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
...
120Ω
Terminating
Resistor
A
B
A
B
REF
A
B
.
.
.
Last in Daisy Chain
Shield
Last in Daisy Chain
Earth Ground
Only at one end
120Ω
Terminating
Resistor
A
B
REF
A
B
A
B
Shield
Drain
Wire
COM 1
COM 2
REF
REF
A
A
B
B
120Ω
Terminating
Resistor
1
2
3
3
4
4
4
USB PORT 2
USB PORT 1
USB PORT 3
USB PORT 4
ETHERNET 1
C
ETHERNET 2
L
DP
HDMI
USB PORT 2
USB PORT 1
USB PORT 3
USB PORT 4
ETHERNET 1
C
ETHERNET 2
L
DP
HDMI