Electro-Voice 1252, 250 operation manual Chapter Communication Wiring, Communication Overview

Chapter 5

Communication Wiring

5.1: Communication Overview

RS-232 communication is used to connect a single Nexus 1250/1252 Meter with another device, such as a computer, RTU or PLC. The link is viable for a distance up to 50 feet (15.2 m) and is available only through the Nexus 1250/1252 Meter’s Port 1. You must set the selector switch beneath the port to RS-232 (see Figure 5.3).

RS-485 communication allows multiple Nexus Meters to communicate with another device at a local or remote site. The I/O modules and the Nexus Display use RS-485 to communicate with the Nexus Meter. All RS-485 links are viable for a distance up to 4000 feet (1220 m). Ports 1 through 4 on the Nexus 1250/1252 Meter are two-wire, RS-485 connections operating up to 115,200 baud. To use Port 1 for RS-485, set the selector switch to RS-485 (see Figure 5.3).

Nexus

RS-232 1 device, 50 feet maximum, Nexus Port 1

Nexus

Nexus

Nexus

RS-485	RS-232/485	RS-232
	Converter
	(Unicom 2500)

Up to 31 Devices, 4000 feet maximum (without a

repeater), connected in series via RS-485 (daisy chain)

Nexus

RS-232

Null Modem

MODEM

Nexus

Nexus

Nexus

RS-485

RS-232/485 Converter

(Modem Manager)

RS-232

MODEM

Telephone Line,

Fiber Optic Link or

Radio Link

Figure 5.1: Communication Overview

e Electro Industries/GaugeTech Doc # E107706 V1.25 5-1