Electro Industries/GaugeTech Nexus 1250, Installation & Operation Manual

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Nexus P40N Display, Back View
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Electro Industries/GaugeTech
Doc #: E107-7-06-121
5-11
5.8: RS-485 Connection 5.8: RS-485 Connection— —Nexus Monitor to the Nexus P40N External Display Nexus Monitor to the Nexus P40N External Display
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Insert one end of the supplied RS-485 cable into port 3 of the Nexus Monitor. Port 3 is factory-set to
match the Nexus Display’s baud rate of 9600. To use a port other than port 3, you must set the port’s
baud rate to 9600 using the Nexus Communicator software (see the
Nexus Communicator User
Manual ). Insert the other end of the cable into the back of the Nexus P40N Display. The connectors
fit only one way into the ports.
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The cable harness brings 17 VDC to the displays from the Nexus Monitor, represented by dashed
lines in the figure below. RS-485 communication is capable for up to 4000 feet (1219 meters). If
your cable length exceeds 200 feet you must use a remote power supply, such as EIG’s Power Brick
(model # PB1), and:
•
Connect the shield to the shield (S) terminal on the Nexus Display port. The (S) terminal on the
Nexus is used to reference the Nexus port to the same potential as the source. It is not an
earth-ground connection. You must also connect the shield to earth-ground at one point.
•
Provide termination resistors at each end, connected to the A(+) and B(-) lines. RT is
approximately 120 Ohms.
+ V - S B(-) A(+)
A(+) B(-) S - V +
Figure 5.10: Nexus Monitor Connected to Nexus P40N External Display
Nexus P40N Display Port
Nexus Monitor Port 3
RT
RT
V+
V-
S
B(-)
A(+)
Top
Bottom
Courtesy of NationalSwitchgear.com