Allen-Bradley HI1769-WS CompactLogix Weigh Scale Module

The Allen-Bradley HI1769-WS, also cataloged as the 1769-WS Weigh Scale Module, operates as a dedicated hardware component for load cell signal conditioning and strain gauge digitizing within CompactLogix controller platforms. This single-channel module converts millivolt signals from strain gauge load cells directly into high-resolution integer and floating-point weight registers on the controller backplane, bypassing external transmitter hardware.

Hardware Specifications

Backplane Bus Communication & Strain Gauge Processing

The module integrates directly with the 1769 Compact I/O backplane bus to deliver high-velocity data transfers at up to 100 weight updates per second. Internal signal conditioning utilizes C2 electronic calibration algorithms alongside WAVERSAVER vibration attenuation filtering to eliminate mechanical noise above 0.25 Hz. Backplane power draw stays below 0.5 A at 5 VDC, while internal diagnostic routines continually monitor load cell excitation current, sense voltage levels, and channel integrity to preserve measurement stability across dynamic batching and filling operations.

Frequently Asked Questions

Q: How many load cells can be powered and processed by a single HI1769-WS module?

A: A single module provides 5 VDC excitation power and signal processing for up to four 350-ohm strain gauge load cells connected in parallel.

Q: Can the module be calibrated without using physical test weights?

A: Yes. The module supports Hardy C2 electronic calibration, which reads factory-stored calibration data directly from C2-certified load cells across the field wiring, eliminating the need for test weights.

Q: What mechanism prevents mechanical plant vibration from corrupting weight readings?

A: The module incorporates selectable WAVERSAVER digital filtering technology that suppresses mechanical vibration noise at frequencies down to 0.25 Hz across 5 user-configurable steps.

Field Installation Guidelines

Mount the module on a standard 35 mm DIN rail or secure it to an enclosure backplate using M4 hardware. Seat the tongue-and-groove side connectors firmly into the adjacent CompactLogix module and engage the backplane locking lever. Route strain gauge signal conductors using shielded, twisted-pair cable isolated from high-voltage AC cables, variable frequency drives, and heavy inductive equipment. Connect the cable shield to a single-point system ground at the module terminal block or junction box to maintain a 100 dB common mode rejection ratio. Ensure ambient cabinet operating temperatures remain between 0 and 60 deg C with relative humidity within 5 to 95% non-condensing.