GE UR8AH

Description

Product Overview

The GE UR8AH is an 8-channel DC analog input module designed for the GE Series 90-30 PLC family. This module serves as a critical interface for connecting a variety of voltage and current signals from field transmitters and sensors to the PLC system, enabling precise monitoring and control of analog process variables. The versatility and reliability of the GE UR8AH make it a fundamental component for data acquisition in industrial automation applications.

Key Product Parameters

• Product Type: Analog Input Module

• Compatible System: GE Series 90-30 PLC

• Channels: 8 single-ended input channels.

• Input Signal Types: Configurable per channel for a range of signals, typically including:

  • 0-10V DC

  • 0-5V DC

  • 1-5V DC

  • 0-20mA (often with a 250-ohm internal resistor for voltage conversion)

  • 4-20mA (with internal 250-ohm resistor)

• Resolution: 12-bit analog-to-digital conversion, providing 4096 counts of resolution.

• Input Impedance: High impedance for voltage inputs (e.g., 1 MΩ).

• Isolation: Channel-to-bus isolation (500 VAC), but channels share a common ground (not isolated from each other).

• Update Time: Varies based on the number of active channels and the PLC’s scan time.

• Connection: Uses a removable terminal block for field wiring.

Advantages and Core Features

The primary advantage of the GE UR8AH is its channel-by-channel configurability, allowing a single module to interface with a mix of different sensor types within one application. This flexibility simplifies spare parts inventory and system design. Its 12-bit resolution provides sufficient accuracy for most industrial monitoring tasks. The module integrates easily into the 90-30 rack and is configured entirely within the PLC programming software (Proficy Machine Edition or earlier Logicmaster), making commissioning straightforward. The UR8AH is a proven, reliable workhorse for analog input requirements in the 90-30 ecosystem.

Application Scenarios

This module is used across industries for monitoring continuous process variables:

• Process Control: Reading 4-20mA signals from pressure, temperature, level, and flow transmitters in chemical or water treatment plants.

• Environmental Monitoring: Measuring 0-10V signals from humidity sensors, gas detectors, or light sensors in building management systems.

• Machine Monitoring: Interfacing with analog tachometers, load cells, or potentiometers on production machinery.

• Energy Management: Submetering by reading 0-5V or 4-20mA outputs from power monitors and transducers.

Comparison with Competing Products

Within the 90-30 family, the GE UR8AH is a standard-density analog input module. Competing products from other manufacturers include the Siemens SM331 analog input for S7-300 or the Allen-Bradley 1769-IF8 for CompactLogix. The UR8AH is distinguished by its specific integration with the 90-30 backplane and software, offering a cost-effective and reliable solution for existing installations. Compared to newer, more advanced modules, it lacks features like channel-to-channel isolation or higher 16-bit resolution but remains a practical choice for standard applications.

Selection Guide and Important Notes

Selecting the GE UR8AH requires confirming compatibility with the 90-30 CPU and rack, and planning the signal type for each channel.

Important Precautions:

• Common Ground Limitation: All 8 channels share a common analog return (AGND). Do not use this module for signals from devices with different ground potentials, as it will create ground loops and cause measurement errors.

• Configuration is Mandatory: Each channel must be correctly configured in the PLC hardware configuration for its specific input type (e.g., 4-20mA, 0-10V). An incorrect setting will yield invalid data.

• Noise Immunity: Due to the lack of channel-to-channel isolation, use shielded twisted-pair cables for analog signals and follow proper grounding practices, especially in electrically noisy environments.

• Current Inputs: For current inputs (0-20mA, 4-20mA), the module uses an internal 250-ohm resistor to convert the signal to a voltage. Ensure the field device can drive this load.

• Power Budget: Verify that the PLC rack’s power supply has sufficient capacity to power the UR8AH and all other installed modules.

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