A&D AD-4404 Checkweighing Controller

Overview

The A&D AD-4404 Checkweighing Controller is a high-speed, industrial-grade weighing control unit engineered for integration into automated belt-based checkweighing and multi-stage sorting systems. Designed and manufactured in Japan, it operates on the principle of dynamic load cell signal acquisition and real-time mass computation, supporting precise weight verification under continuous motion—critical for food, pharmaceutical, chemical, and consumer goods production lines where throughput and regulatory compliance are non-negotiable. The controller processes analog signals from load cells or weighing bridges via a high-fidelity 24-bit sigma-delta A/D converter, delivering stable, noise-immune measurement performance even under vibration-prone conveyor environments. Its architecture supports both static and dynamic zero tracking, enabling automatic drift correction during operation without interrupting production flow—a fundamental requirement for GLP- and GMP-aligned manufacturing environments.

Key Features

• High-speed sampling at 100 Hz ensures accurate capture of transient weight events across fast-moving conveyor belts (up to 200+ units per minute).
• Internal A/D resolution of 1:1,000,000 and display resolution of 1:16,000 support fine-grained weight discrimination—essential for tight-tolerance applications such as tablet or capsule weight control per USP & JP pharmacopeial standards.
• Five built-in checkweighing modes—including Auto, Belt-Stop, OK-only, Manual, and Simplified—allow flexible deployment across diverse line configurations and operator skill levels.
• Dual zero-tracking algorithm (static + dynamic) combined with real-time dynamic compensation maintains measurement integrity during belt acceleration, deceleration, and intermittent loading conditions.
• Dust-resistant front-panel design meets IP54-rated operational durability requirements for humid or particulate-laden factory settings.
• Digital calibration procedure eliminates mechanical potentiometer dependency, ensuring long-term traceability and repeatability compliant with ISO/IEC 17025 calibration documentation practices.
• Standard RS-485 serial interface and 4–20 mA current loop output enable seamless integration with PLCs, SCADA systems, and MES platforms—supporting audit-ready data logging when paired with compatible software.

Sample Compatibility & Compliance

The AD-4404 is not a standalone scale but a dedicated controller optimized for use with tension-type or bending-beam load cells mounted on conveyor-integrated weighing platforms. It accommodates standard 350 Ω or 1,000 Ω bridge configurations and supports excitation voltages up to 15 V DC. Its input circuitry includes configurable filtering and gain adjustment to match sensor output characteristics, minimizing signal conditioning hardware requirements. For regulated industries, the unit’s deterministic response time, repeatable calibration protocol, and deterministic I/O behavior align with FDA 21 CFR Part 11 expectations when deployed within validated system architectures. While the AD-4404 itself does not carry CE, UL, or SIL certification, its modular I/O options—including relay outputs for reject actuation and analog outputs for trend monitoring—are designed to interface with externally certified safety controllers in accordance with IEC 61508 and ISO 13849-1 functional safety frameworks.

Software & Data Management

The AD-4404 operates as an embedded control node rather than a PC-dependent instrument; all logic execution, mode switching, and threshold evaluation occur locally without host dependency. Configuration and parameter setting are performed via the front-panel keypad and fluorescent display—eliminating external software dependencies and reducing validation overhead. However, when connected to higher-level systems via RS-485 or optional RS-232, it supports Modbus RTU protocol for bidirectional register access (e.g., reading weight values, updating setpoints, triggering calibration sequences). Audit trails—such as calibration timestamps, mode changes, and fault logs—are retained in non-volatile memory and can be polled programmatically. For facilities requiring full electronic record retention, integration with third-party MES or LIMS platforms enables timestamped weight data export with user ID attribution and change history—meeting ALCOA+ principles for data integrity in pharmaceutical and nutraceutical manufacturing.

Applications

• Multi-stage inline checkweighing in snack food packaging lines, verifying fill weight consistency before metal detection and case packing.
• Pharmaceutical tablet/capsule weight sorting prior to blister packaging, supporting statistical process control (SPC) and real-time OOS flagging.
• Chemical powder bagging verification, where overfill/underfill detection triggers automatic line stoppage or diverter activation.
• Integration with X-ray or optical foreign material detection systems—using the AD-4404’s dedicated “foreign object input” terminal to synchronize weight anomaly alerts with imaging event timestamps.
• High-speed bottle/can filling line verification in beverage manufacturing, where dynamic compensation compensates for liquid slosh effects during transit over the weigh bed.

FAQ

Does the AD-4404 support Ethernet or USB connectivity?

No—native Ethernet or USB interfaces are not available. Communication is limited to RS-485 (standard), RS-232 (optional OP-04-4402), or analog/current-loop outputs. Industrial Ethernet gateways may be used externally for protocol translation.
Can the AD-4404 perform statistical analysis (e.g., Cpk, mean, SD) internally?

No—it performs real-time pass/fail classification only. Statistical calculations require external data collection and analysis tools.
Is firmware upgrade supported in the field?

Firmware updates are possible via RS-232 using A&D’s proprietary utility software, but require authorized service personnel and factory-issued update files.
What load cell excitation voltage does the AD-4404 provide?

The unit supplies adjustable excitation voltage between 5 V DC and 15 V DC, configurable per installation requirements and sensor specifications.
How is calibration traceability maintained?

Digital calibration stores reference values in EEPROM with date/time stamping. Full calibration records—including standard weights used, environmental conditions, and operator ID—must be documented externally per ISO/IEC 17025 Clause 6.6 requirements.