ALLEN BRADLEY 1762-OF4 Product Description

Overview

ALLEN BRADLEY 1762-OF4 is a MicroLogix 4-channel analog output module for the Allen-Bradley Bulletin 1762 expansion I/O family, compatible with MicroLogix 1200 and related MicroLogix 1762 control systems. The module provides 4 single-ended unipolar analog outputs for driving external analog devices, control valves, drives, proportional controllers, meters and other field actuators from PLC control signals. It supports both voltage and current analog output signals, with isolated I/O wiring for industrial control cabinet installation. The 1762-OF4 is an active mature Rockwell Automation MicroLogix analog output module, used as a replacement I/O spare in existing MicroLogix control installations.

Features

ALLEN BRADLEY 1762-OF4 provides four analog output channels configured as single-ended unipolar outputs. The module supports voltage and current output types; the analog normal operating range covers 0 to 10 V DC voltage and 4 to 20 mA current, while full-scale analog ranges cover 0 to 10.5 V DC voltage and 0 to 21 mA current. Output resolution is 12 bit unipolar. The D/A converter uses an R-2R ladder voltage switching architecture.

Output update time is a typical 2.5 ms. Voltage output load range is greater than 1 kΩ, and current output resistive load is 0 to 500 Ω, including wire resistance. Reactive load limits are less than 0.1 mH for current output and less than 1 μF for voltage output. Non-linearity is less than ±0.59 percent of full scale, output ripple is less than ±0.1 percent at 0 to 500 Hz referred to the output range, and repeatability is -0.12 to 0.12 percent. Typical overall accuracy is ±1.17 percent of full scale at -20 to 65 degrees Celsius, applicable to Series B I/O modules.

The module includes continuous open and short-circuit protection for outputs, with output protection at -32 mA per Rockwell data. Input and output groups are isolated from the system with 30 V AC and 30 V DC rated working voltage, using IEC Class 2 reinforced insulation type tested at 500 V AC or 707 V DC for one minute. Bus current draw is a maximum of 40 mA at 5 V DC and 165 mA at 24 V DC. The module supports hazardous location Class I, Division 2 Groups A, B, C and D, and includes ESD and industrial immunity protection for cabinet-mounted PLC installations.

Specs

Product series: Allen-Bradley Bulletin 1762 MicroLogix expansion I/O Model: ALLEN BRADLEY 1762-OF4Type: 4-channel analog output module Compatible controllers: MicroLogix 1200 and compatible MicroLogix 1762 expansion I/O systems Number of outputs: 4 single-ended unipolar channels Output signal types: Voltage and current analog outputs Normal operating voltage range: 0 to 10 V DCNormal operating current range: 4 to 20 mAFull-scale voltage range: 0 to 10.5 V DCFull-scale current range: 0 to 21 mAD/A converter: R-2R ladder voltage switchingResolution: 12 bit unipolar Output update time: Typical 2.5 msVoltage output load: Greater than 1 kΩCurrent output resistive load: 0 to 500 Ω, including wire resistance Reactive load, current output: Less than 0.1 mHReactive load, voltage output: Less than 1 μFNon-linearity: Less than ±0.59 percent of full scale Output ripple: Less than ±0.1 percent at 0 to 500 HzRepeatability: -0.12 to 0.12 percentOverall accuracy: ±1.17 percent full scale at -20 to 65 degrees Celsius, Series B Output protection: Continuous open and short-circuit protection; -32 mA output protection I/O isolation: 30 V AC / 30 V DC rated working voltage, IEC Class 2 reinforced insulation Bus current draw: Maximum 40 mA at 5 V DC; 165 mA at 24 V DCDimensions: Width 40 mm, height 90 mm, depth 87 mmShipping weight: Approximately 235 g with carton Operating temperature: -20 to 65 degrees CelsiusStorage temperature: -40 degrees Celsius lower range Operating humidity: 5 to 95 percent non-condensing Operating altitude: 2000 mHazardous location: Class I, Division 2 Groups A, B, C, DCountry of origin: MalaysiaProduct status: Active mature Rockwell Automation MicroLogix analog output module

Principle

ALLEN BRADLEY 1762-OF4 operates as a digital-to-analog output interface between the MicroLogix PLC and external analog field devices. The controller writes digital output values to the module for each analog channel. The module converts these digital values into scaled voltage or current analog signals using the R-2R ladder D/A converter and outputs them to connected valves, drives, meters, proportional controllers or other analog actuators. The analog signal level corresponds to the PLC-programmed setpoint, control output or process command.

Output protection continuously monitors the analog channels for open-circuit or short-circuit conditions, helping protect the module and connected field devices. The isolated I/O group separates field output wiring from the controller system, reducing ground-loop noise and protecting cabinet electronics. The bus supply powers the module electronics and D/A conversion circuitry, while the output load and reactive limits must stay within the rated ranges for stable analog performance. Shielded cable such as Belden 8761 is recommended for analog output wiring to reduce industrial electrical noise.

Applications

ALLEN BRADLEY 1762-OF4 is used in MicroLogix PLC systems that need analog control signals for voltage or current field actuators. It fits control valves, dampers, variable frequency drives, proportional control valves, motor speed controllers, analog meters, recording instruments, setpoint stations, hydraulic and pneumatic proportional devices, process control loops, production lines, packaging machines, material handling, test benches, machine tools, water and wastewater, utilities, chemical processing, pulp and paper, and general industrial control panels. In existing MicroLogix installations originally equipped with the 1762-OF4, the module serves as a direct replacement analog output spare, compatible with the original 1762 base mounting, screw wiring and PLC I/O configuration.