ALLEN BRADLEY 1769-2WS CompactLogix Weigh Scale Module

The ALLEN BRADLEY 1769-2WS, also cataloged as the 1769-2WS Weigh Scale Module, operates as a dedicated hardware component for strain gauge load cell signal processing within CompactLogix and MicroLogix 1500 systems. Designed with 2 independent load cell channels, the unit converts raw millivolt signals from -0.3 mV to +15.3 mV into 24-bit digital weight values. The module supplies an integrated 5 VDC excitation voltage to power up to 8 parallel strain gauge transducers, delivering direct force measurement to controller logic without external transmitter signal conditioning.

Hardware Specifications

Deterministic Network Integration & I/O Density Scaling

The 1769-2WS streams weight, tare, and rate-of-change data across the CompactLogix backplane at up to 100 updates per second, maintaining backplane bus communication velocity across EtherNet/IP deterministic networks. The module supports electronic (C2) and traditional test-weight calibration procedures directly within RSLogix 5000 and Studio 5000 Logix Designer software. Firmware flash compatibility ensures seamless I/O density scaling and diagnostics processing—including load cell overload and open-circuit wire fault detection—without disturbing backplane synchronization.

Frequently Asked Questions

Q: How many load cells can be connected to a single 1769-2WS module?

A: The module supplies sufficient 5 VDC excitation current to drive up to 8 standard 350-Ohm strain gauge load cells in parallel across its two channels.

Q: Can the 1769-2WS execute tare and calibration procedures directly over the controller backplane?

A: Yes, operators execute electronic (C2) calibration, traditional span calibration, and tare adjustments directly via RSLogix 5000 / Studio 5000 software tag parameters.

Field Installation Guidelines

Mount the 1769-2WS module onto an IEC standard DIN rail or panel surface using the integrated mounting feet, ensuring the bus lever locks securely into the adjacent 1769 Compact I/O module or controller backplane interface. Confirm the module is positioned within its maximum power supply distance rating on the I/O bank.

Connect load cell sense and signal lines using 4-wire or 6-wire shielded, twisted-pair cables. Ground cable shields at a single point on the enclosure ground bus bar to suppress high-frequency electrical noise and common-mode signal corruption. Keep all low-level mV signal wiring physically separated from high-voltage AC lines and variable frequency drive motor cables.