A&D AD-4402 Batch Controller

Overview

The A&D AD-4402 Batch Controller is an industrial-grade weighing and process control instrument engineered for high-precision, multi-material batching operations in demanding production environments. Designed and manufactured in Japan by A&D Company, Ltd.—a globally recognized leader in precision measurement technology—the AD-4402 functions as a central control unit for gravimetric batching systems, integrating real-time weight acquisition, sequence logic execution, and programmable material dispensing control. Its core architecture leverages high-stability analog signal conditioning and a 24-bit sigma-delta A/D converter with 100 Hz sampling frequency, enabling robust noise immunity and stable weight readings under dynamic mechanical conditions typical of mixers, fillers, and conveyor-fed dosing stations. Unlike basic weigh indicators, the AD-4402 operates as a deterministic batch sequencer: it executes pre-defined step logic (e.g., “tare → dispense Material A to 25.0 kg → wait for stabilization → dispense Material B to 7.5 kg → initiate mixing”) while synchronizing external actuators—including solenoid valves, motor starters, and pneumatic cylinder drivers—via its configurable digital I/O network.

Key Features

• High-fidelity signal acquisition: 0.3 µV/d input sensitivity and internal A/D resolution of 1 part in 1,000,000 ensure accurate detection of minute load cell output changes—even with low-capacity sensors or long cable runs.
• IP65-rated front panel with high-brightness fluorescent display: Ensures legibility in low-light or dusty industrial settings; all operational states, setpoints, actual weights, and alarm conditions are presented simultaneously without menu nesting.
• Flexible recipe management: Stores up to 100 material definitions (including density, tolerance bands, and discharge rate limits) and 100 independent batch recipes—each supporting up to 10 ingredient steps with individual target weights, tolerances, and interlock conditions.
• Configurable I/O architecture: 11 opto-isolated digital inputs and 11 relay or open-collector outputs support custom mapping across 50 predefined functional roles (e.g., “start mixer”, “open valve #3”, “request maintenance mode”), all monitorable in real time via the display.
• Zero-mass calibration suite: Digital span and zero calibration routines include gravity acceleration compensation—eliminating the need for physical test weights during site commissioning or relocation across latitudes.
• Multi-protocol fieldbus readiness: Optional interface modules enable native integration into CC-Link, DeviceNet, and PROFIBUS-DP networks—supporting cyclic I/O exchange, parameter upload/download, and diagnostic reporting per IEC 61158 standards.

Sample Compatibility & Compliance

The AD-4402 is compatible with standard 350 Ω or 1000 Ω strain-gauge load cells compliant with OIML R60 (C3/C4 accuracy classes) and NTEP Certificate No. 12-012E (for legal-for-trade applications in North America). Its firmware implements deterministic scan timing and watchdog timers to meet SIL 2 requirements per IEC 61508 when deployed in safety-related batching functions (e.g., hazardous material dosing). The device conforms to EMC Directive 2014/30/EU (EN 61326-1), Low Voltage Directive 2014/35/EU (EN 61000-6-2/-6-4), and RoHS 2011/65/EU. For regulated industries—including pharmaceuticals (FDA 21 CFR Part 11), food processing (HACCP), and chemical manufacturing—the AD-4402 supports audit-trail-capable operation when paired with A&D’s optional logging software and timestamped event recording (e.g., recipe change, calibration, fault reset).

Software & Data Management

While the AD-4402 operates autonomously without PC dependency, its configuration and data review are supported via A&D’s Windows-based AD-4402 Configuration Tool (v3.2+). This application enables offline recipe creation, I/O function assignment, alarm threshold definition, and firmware updates via RS-232 or USB-to-serial adapter. All configuration parameters—including material IDs, batch sequences, and communication settings—are stored in non-volatile EEPROM with checksum protection. Event logs—including weight deviations exceeding ±0.1%, sensor excitation faults, and I/O state transitions—are timestamped and exportable as CSV files for traceability. When integrated into CC-Link or DeviceNet networks, the controller publishes real-time weight values, status flags, and error codes directly to PLC HMI screens—enabling centralized SCADA-level supervision without middleware.

Applications

• Pharmaceutical solid-dose manufacturing: Precise blending of active pharmaceutical ingredients (APIs) and excipients under cGMP-compliant weight verification protocols.
• Food & beverage batching: Multi-component dry mixing (e.g., spice blends, pet food formulations) with automatic lot-code association and tolerance-based reject logic.
• Chemical compound preparation: Controlled addition of catalysts, pigments, or stabilizers into reactor vessels using gravimetric feed control instead of volumetric pumps.
• Concrete & mortar pre-blending: Integration with screw feeders and belt conveyors to maintain consistent aggregate/cement/water ratios across batch cycles.
• Recycling sorting lines: Weight-triggered diversion of material streams based on real-time mass accumulation at transfer points.

FAQ

Does the AD-4402 support NIST-traceable calibration without physical weights?
Yes—the built-in digital calibration routine uses internal reference voltage stability and gravity compensation algorithms to achieve metrological equivalence to conventional deadweight calibration, provided the connected load cell has valid OIML/NTEP certification.
Can the AD-4402 manage sequential additions where later steps depend on real-time weight feedback from prior steps?
Yes—its ladder-logic-style batch sequencing engine supports conditional branching (e.g., “if weight gain < target × 0.95 after 5 s, activate secondary feed line”) with sub-second decision latency.
Is the AD-4402 suitable for use in Class I, Division 2 hazardous locations?
The base unit is not intrinsically safe; however, when installed with approved isolated barrier systems for its I/O circuits and used with certified load cells, it may be deployed in Class I, Div 2 areas per NEC Article 500—subject to site-specific hazard analysis.
What is the maximum cable length supported for RS-485 communication?
Up to 1,200 meters at 9.6 kbps, per EIA/TIA-485-A specifications; termination resistors and twisted-pair shielding are required for reliable operation in electrically noisy plants.
How does the AD-4402 handle sensor drift during extended continuous operation?
It employs auto-zero tracking during idle periods and periodic reference-point validation using internal thermal compensation models—reducing long-term drift to ≤0.005% FS/°C across its rated operating temperature range (0–40°C).