High-Precision Control for Hydraulic Drive Systems

The Rexroth VT-HNC100-1-23/W-08-C-0 (R900959000) represents the pinnacle of digital control technology specifically engineered for hydraulic drives. Unlike standard electronic controllers, the HNC100 series is built to understand the unique physical properties of fluid power, such as oil compressibility, non-linear flow through proportional valves, and varying cylinder area ratios. This controller provides a deterministic, high-speed solution for managing a single hydraulic axis in safety-critical and high-performance industrial environments.

By integrating high-speed 32-bit digital signal processing (DSP), the VT-HNC100-1-23 ensures that motion profiles are executed with millisecond-level precision. This hardware revision (23) is optimized for reliability and thermal stability, making it the preferred choice for machine builders who require consistent accuracy across thousands of operating hours.

Functional Intelligence and Design Characteristics

Multi-Loop Control Logic

The VT-HNC100-1-23/W-08-C-0 is equipped with versatile control loop structures. It allows for independent or combined control of position, speed, and pressure/force. A significant advantage of this system is the "on-the-fly" transition between control modes. For example, in a pressing application, the controller can manage a high-speed approach in position-control mode and transition seamlessly to pressure-control mode upon mechanical contact without causing hydraulic shock or pressure spikes.

SSI and Incremental Feedback Compatibility

Achieving micron-level precision requires robust feedback. The R900959000 supports SSI (Synchronous Serial Interface) for absolute linear transducers, ensuring the system retains its position data even after a power cycle. For high-speed velocity monitoring, incremental encoder support provides the necessary resolution to maintain stable motion even at extremely low speeds, which is often a challenge in hydraulic systems.

Optimized Hydraulic Algorithms

A core differentiator of the VT-HNC100 is its library of specialized hydraulic functions. It includes automatic compensation for cylinder area ratios, ensuring that the control gains are correctly adjusted regardless of whether the cylinder is extending or retracting. Additionally, it features valve linearization tables that counteract the non-linear flow-to-voltage characteristics of proportional and servo valves, resulting in a perfectly linear and predictable machine response.

Primary Industrial Applications

The robust design and high precision of the R900959000 make it ideal for various sectors:

• Metal Forming: Precise control of pressing force and position in synchronized hydraulic presses.

• Plastic Injection Molding: Managing the injection stroke and clamping pressures with high repeatability.

• Wood Processing: High-speed positioning of saws and planers where hydraulic power is required.

• Metallurgy: Operating ladle tilting or roller adjustment axes in harsh, high-interference environments.

Programming and Commissioning

Commissioning of the Rexroth VT-HNC100-1-23/W-08-C-0 is streamlined through the WIN-HNC software. This PC-based environment provides an intuitive interface for defining motion sequences and tuning PID parameters. The software also features a built-in oscilloscope function, allowing technicians to visualize command vs. actual values in real-time. This is critical for identifying mechanical resonance or tuning out hydraulic oscillations during the setup phase.

Hardware installation is simplified by the sub-plate mounting format and clearly labeled digital I/O (W-08). The 8 digital inputs and outputs provide localized control for limit switches, proximity sensors, and status indicators, effectively turning the HNC100 into a localized logic hub for the hydraulic axis it manages.