Electro Industries/GaugeTech Nexus 1250, Installation & Operation Manual

Page: 48 / 115

– – + + G
A(+) B(-) S - V + A(+) B(-) S - V +
+ V - S B(-) A(+) + V - S B(-) A(+) + V - S B(-) A(+) + V - S B(-) A(+)
8 7 6 5 4 3 2 1 C - +
Port 1
RS-232 or
RS-485 (Set)
RS-232
RS-485
Port 2
Normally Slave
Modem/Ethernet Gateway
High Speed Inputs IRIG-B
RS-485 Master
Unicom or Modem Manager
Nexus P40N External Display
Nexus I/O Module
RS-232 Extension
Cable
(1 to 1 wiring)
I/O Modules and Display
require power connections
to the +/- voltage
terminals (dashed lines).
For all communications: S=Shield. This connection
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.
RT=
~120 Ohms
RT=
~120 Ohms
RT=
~120 Ohms
RT=
~120 Ohms
RT=
~120 Ohms
RT=
~120 Ohms
e
Electro Industries/GaugeTech
Doc #: E107-7-06-121
5-4
Port 3 Port 4
Figure 5.4: Communication Wiring
NOTE: You may use ANY port to connect a Nexus Display or RS-485 Master. However, if you
are using the Internal Modem (or Network) Option, Port 2 is labeled Modem (Ethernet) Gateway.
Ports 1, 3 and 4 DO NOT change.The I/O Modules MUST use Port 4 (Port 3 is an alternate). The
Nexus P40N Display is shipped programmed to use Port 3—see section 5.7 for details.
Courtesy of NationalSwitchgear.com