Description

Allen-Bradley 1769-2WS Weigh Scale Module

The Allen-Bradley 1769-2WS, also cataloged as the 1769-2WS Weigh Scale Module, operates as a dedicated hardware component for load cell signal measurement within CompactLogix and MicroLogix 1500 controller platforms. It processes millivolt strain gauge inputs and provides excitation output for weighing applications.

Hardware Specifications

Parameter	Specification
Model	1769-2WS
Brand	Allen-Bradley
Origin	United States
Product Type	Weigh Scale Module
Series	CompactLogix 1769 Compact I/O
Weight	2.00 lbs (0.91 kg)
Dimensions	Not specified
Operating Temp	0 to 60 deg C (32 to 140 deg F)
Power Consumption	< 0.5 A at 5.1 VDC from backplane
Module Type	Dual-channel weighing scale input module
Compatible Controllers	CompactLogix and MicroLogix 1500
Input Channels	2 channels
Input Signal Range	-0.3 mV to +15.3 mV
Sense Input	+5 VDC
Excitation Output	+5 VDC
Backplane Current	< 0.5 A at 5 VDC
Maximum Load Cells Supported	Up to 8 load cells
Internal Resolution	1:8,388,608
Update Rate	100 updates per second
Conversion Rate	100 updates per second
Compatible Transducers	Strain gauges, load sensors, load cells
Weighing Modes	Net, Gross, Rate-of-change
Calibration Method	Electronic C2 calibration and traditional test weight calibration

EtherNet/IP and Backplane Integration Characteristics

The 1769-2WS integrates with Allen-Bradley CompactLogix architectures through the 1769 backplane bus interface. Therefore, the module exchanges weighing data with the controller while maintaining the defined I/O update cycle. The module supports industrial control configurations that require I/O density scaling across CompactLogix systems. In addition, its firmware architecture follows the Compact I/O platform compatibility requirements for controller communication.

The module converts low-level load cell signals from -0.3 mV to +15.3 mV into controller-readable weighing data. Furthermore, it supplies +5 VDC excitation power for connected load cells and supports multiple load cell configurations through parallel sensor wiring.

Frequently Asked Questions

Q: What type of input signals does the 1769-2WS accept?
A: The module accepts strain gauge and load cell signals within a -0.3 mV to +15.3 mV input range and provides +5 VDC excitation output.

Q: How many load cells can the 1769-2WS support?
A: The module supports connection of up to eight load cells depending on the system wiring configuration and sensor specifications.

Q: Does the 1769-2WS require external power?
A: No. The module receives operating power from the CompactLogix backplane and draws less than 0.5 A at 5.1 VDC.

Field Installation Guidelines

• Install the 1769-2WS module on a compatible 1769 Compact I/O backplane following Allen-Bradley installation procedures.
• Connect load cell wiring with proper signal polarity to maintain accurate millivolt measurement.
• Use shielded instrumentation cable for load cell connections and terminate cable shields according to site grounding practices.
• Keep load cell signal wiring separated from high-voltage power conductors and sources of electrical interference.
• Verify excitation voltage and sensor wiring before applying system power.
• Perform calibration procedures after installation using either electronic C2 calibration or approved test weights.
• Confirm controller I/O configuration matches the installed module type before placing the system into operation.

Specifications

• Brand: Allen Bradley

Advantages

• High reliability in industrial environments
• Supports continuous operation
• Compatible with major PLC/DCS systems