Electro-Voice 1252, 250 operation manual RS-232 Connection-Nexus Meter to a Computer

5.2: RS-232 Connection—Nexus Meter to a Computer

Use Port 1 for RS-232 communication. Set the selector switch beneath the port to RS-232.

Insert one end of an RS-232 extension cable into the Nexus Meter’s 9-pin female serial port. Insert the opposite end into a port on the computer.

The RS-232 standard limits the cable length to 50 feet (15.2m).

The RS-232 Port is configured as Data Communications Equipment (DCE).

Nexus Meter Port 1

RS-232 Port	RS-485 Port
Pin #2=Transmit	(see Section 5.3 for details)
Pin #3=Receive
Pin #5=Ground
+ V -	S B(-) A(+)

5	4	3	2	1
9	8	7	6	Switch set for RS-232 communication

RS-232 RS-485

Figure 5.5: Nexus Port 1—RS-232/RS-485 Communication

5.3: Nexus RS-485 Wiring Fundamentals (with RT Explanation)

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 1250/1252 Meter supplies 17V DC through the +V- ter- minal 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.

SShield: 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.

e Electro Industries/GaugeTech Doc # E107706 V1.25 5-5