B&B Electronics RT12-2222-ZP-12 manual Typical Application 4-20 mA to Voltage Conversion

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Typical Application: 4-20 mA to Voltage Conversion

This section will describe how a typical system is converted from a 4-20mA or 0- 20mA current signal to a 1-5Vdc or 0-5Vdc voltage signal.

The RT series RTU’s do not allow for a direct 4-20mA connection. A simple 250 Ohm, 1%, ¼ Watt, resistor from the input of the respective terminal to ground will convert the current signal to a voltage signal. If a 250 Ohm resistor is not available a 249 Ohm, 1%, ¼ Watt, resistor will work.

The same example is true for a 0-20mA current signal. The only exception is the voltage will swing from 0-5Vdc. If a current source is applied to a respective input without a resistor the data will not be correct and a signal error will occur.

The example below shows analog Input 1 converted from 4-20 to 1-5Vdc. Keep in mind, if an RTU is used in Peer to Peer mode, the receiving device will output a 1- 5Vdc voltage on the respective output.

Configuration Cable Description

Serial cable used in configuration and connectivity of B&B Electronics’ RT-series controllers.

Pin#

Connection (color)

Description

DB9-Pin#2

Green

TX

DB9-Pin#3

Red

RX

DB9-Pin#5

Yellow

GND

DB9-Pin#7

Black

CTS

-Use a straight-through, common, Category 5 cable (available from B&B Electronics) for connection to the RT-series RTU’s.

Manual Documentation Number: RT-12 series-4006m

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Manual Documentation Number: RT-12 series-4006m

B&B Electronics Mfg Co Inc – 707 Dayton Rd - PO Box 1040 - Ottawa IL 61350 - Ph 815-433-5100 - Fax 815-433-5104www.bb-elec.comB&B Electronics – Westlink Commercial Park – Oranmore, Galway, Ireland – Ph +353 91-792444 – Fax +353 91-792445www.bb-europe.com

B&B Electronics Mfg Co Inc – 707 Dayton Rd - PO Box 1040 - Ottawa IL 61350 - Ph 815-433-5100 - Fax 815-433-5104www.bb-elec.comB&B Electronics – Westlink Commercial Park – Oranmore, Galway, Ireland – Ph +353 91-792444 – Fax +353 91-792445www.bb-europe.com

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Contents Wireless Modbus I/O Modules Wireless I/O Modules from B&B Electronics Table of Contents For Modbus Slave RTU mode, check and confirm the following Theory of OperationFor Peer-to-Peer mode, check and confirm the following Modbus Overview RT12-4444 Modbus Map Modbus Functions SupportedModbus Register Maps Peer to Peer Overview RT12-2222 Modbus MapTo Connect to a Controller RT12-4444-9T-W20 Front Panel IdentificationConnection Screw Terminal Description Data Activity LED Indicators Power 10.5~28 VdcLink/Sanity LED Indicators Serial RS-232 InterfaceRT12-2222-ZP-S12 Front Panel Identification RT12-4444-9T-W20 External Battery Back-upConnection Screw Terminals Description RT12-0044-ZP-S12 Front Panel Identification RT12-2222-ZP-S12 External Battery Back-upPower 10.5~28 Vdc Typical Application Peer-to-Peer RT12-0044-ZP-S12 External Battery Back-upHardware Set-up Typical Application Peer-to-Peer Typical Application Modbus Typical Application Well Monitor and Control Modbus Typical Application Well Monitor and Control Peer-to-PeerPin# Connection color Configuration Cable DescriptionTypical Application 4-20 mA to Voltage Conversion Configuration/Monitoring Software Main Configuration/Monitoring Software System MapCurrent Controller Settings Controller ConfigurationManual Documentation Number RT-12 series-4006m Master, Slave, Modbus, Peer-to-Peer Connecting / DisconnectingDigital Input Types Modbus ConfigurationRTU Alarms Analog Outputs Resting Voltage Input Voltage Alarm LimitsManual Documentation Number RT-12 series-4006m Third Party Communications Protocol Support Updating/Sending Configuration to RTUDigital Outputs Status Bar