The HE693ADC409 is a high-precision Millivolt Input Module designed for seamless integration with PLC control systems. By enabling direct connection of millivolt-level signals—such as bridged strain gages and load cells—this module eliminates the requirement for external transducers or signal conditioners. Engineered for demanding industrial environments including process automation, weighing systems, and manufacturing, the unit performs high-speed analog-to-digital conversion with 14-bit resolution. The module features integrated digital filtering to maintain signal integrity in electrically noisy settings, significantly reducing instrumentation errors and preventing costly system downtime.

Signal Processing and Hardware Configuration

The module operates through four independent channels, each capable of configurable input ranges at +/- 25 mVdc, +/- 50 mVdc, or +/- 100 mVdc. Configuration is performed directly via software or a Hand-Held Programmer, allowing for rapid deployment. Internally, the device utilizes an integrating A/D converter to ensure high noise rejection. The architecture supports a wide common-mode range of +/- 12 Vdc, ensuring stability during differential signal measurement. Connectivity is managed through a field-removable 20-pin terminal strip, which simplifies maintenance and ensures rapid module replacement without the need to disconnect permanent field wiring.

Features

• Four independent, software-configurable input channels.
• High-resolution 14-bit analog-to-digital conversion.
• Integrated digital filtering for superior noise rejection in industrial environments.
• Direct interface for low-level sensors like load cells and strain gages.
• Field-removable terminal block for efficient maintenance and wiring management.

Technical Specifications

Installation Guidelines

• Ensure the PLC rack power is disconnected before inserting or removing the module.
• Use shielded twisted-pair cabling for all millivolt signal inputs to minimize electromagnetic interference.
• Ground the cable shields at the source end to prevent ground loops.
• Verify that the terminal block is securely seated and locked into the module housing.
• Maintain proper ventilation within the enclosure to ensure the module operates within the 0 to 60 degC temperature range.
• Avoid routing signal cables in parallel with high-voltage AC power lines.

FAQ

What type of sensors can be connected to the HE693ADC409?

This module is specifically designed for low-level millivolt signals, making it ideal for direct connection to strain gages, load cells, and other bridge-type transducers without the need for external signal conditioning.

How is the module configured?

The module is configured via software or a compatible Hand-Held Programmer, allowing for easy selection of input ranges and operational parameters.

Does the module require external power?

The module draws its operating power directly from the PLC backplane (100 mA at 5 Vdc).