Warner Electric CBPC-3590 - Manual (Page 13)

Warner Electric • 800-825-9050 P-291-1 • 819-0526 13
Figure 7b Multiple Unit Wiring
Termination
The RS-422A/485 receivers require termination to
minimize the effects of noise while the bus is not
being driven. The CBPC-3590 incorporates the
terminations shown below internally. When
connection is made to a RS-422/485 device other
than the CBPC-3590, the receiver should be
terminated as shown.
Cable Selection
The CBPC-3590 serial interface uses a simple
interconnect scheme and low cost wiring mak-
ing it superior to parallel data transfer schemes .
Through two (2) wire shielded pairs, remote
operation at distances up to 5,000 feet can be
implemented. The following general guidelines
should be observed .
1. Use # 24 AWG twisted pair, overall shielded
cable .
2 . Use a “daisy chained” connection scheme for
bus systems .
3. If a “multidrop” system is used, keep the drop
length at 10% of the main line.
4. Tie the cable shield to the Building Ground at
the CBPC-3590 end of the cable.
RXD
COM
TXD
RS232 to
RS422/485
Converter
TXD+
TXD-
SHLD
RXD-
RXD+
6
5
4
3
2
1
CBPC-3590
Display/Keypad
Twisted Pairs with Shields
J4
Figure 7a Single Unit Wiring
TXD+
from
CBC-1000
TXD-
2
10 k Ω max. to
100 Ω min.
COM
to
receiver
+5V
RXD
COM
TXD
RS232 to
RS422/485
Converter
TXD+
TXD-
SHLD
RXD-
RXD+
6
5
4
3
2
1
J6
Keypad/Display
CBPC-3590
6
5
4
3
2
1
Keypad/Display
CBPC-3590
J4
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J4 Connections
Pin 6
TXD+
Pin 5 TXD-
Pin 4 RXD-
Pin 3 RXC+
Pin 2 Shield to Chassis End
Pin 1 Shield to Chassis En d