Electro Industries/GaugeTech Nexus 1250, Installation & Operation Manual

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+ V - S B(-) A(+)
e
Electro Industries/GaugeTech
Doc #: E107-7-06-121
5-5
Figure 5.5: Nexus Port 1—RS-232/RS-485 Communication
Switch set for RS-232 communication
RS-232 RS-485
5 4 3 2 1
9 8 7 6
RS-232 Port
Pin #2=Transmit
Pin #3=Receive
Pin #5=Ground
RS-485 Port
(see Section 5.3 for details)
Nexus Monitor Port 1
5.2: RS-232 Connection 5.2: RS-232 Connection— —Nexus Monitor to a Computer Nexus Monitor to a Computer
n
Use Port 1 for RS-232 communication. Set the selector switch beneath the port to RS-232.
n
Insert one end of an RS-232 extension cable into the Nexus Monitor’s 9-pin female serial port. Insert
the opposite end into a port on the computer.
n
The RS-232 standard limits the cable length to 50 feet (15.2m).
n
The RS-232 Port is configured as Data Communications Equipment (DCE).
5.3: Nexus RS-485 Wiring Fundamentals 5.3: Nexus RS-485 Wiring Fundamentals
Nexus RS-485 Ports (Ports 1–4)
(see Figure 5.5 above)
+V- Voltage terminals for power connections
: Use with Nexus I/O Modules and the
Nexus Displays only. The Nexus Monitor supplies 17 VDC through the +V- terminal
connections. Note: Do
not
connect these pins to devices that receive power from
another source—ie, a computer—or to devices that do not require power to operate.
S Shield:
The Shield 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. Do not connect the shield to ground at
multiple points; it will interfere with communication.
A(+)/B(-) Two-wire, RS-485 communication terminals:
Connect the A(+) terminal of the
Nexus Port to the (+) terminal of the device. Connect the B(-) terminal of the Nexus
Port to the (-) terminal of the device.
Courtesy of NationalSwitchgear.com