Advanced Digital Control for Hydraulic Drives

The Rexroth VT-HNC100-1-23/W-08-S-0 is a high-performance digital axis controller designed to bridge the gap between complex industrial motion sequences and hydraulic power. In modern manufacturing, hydraulic axes must often perform with the same precision and repeatability as electromechanical drives. The HNC100 series achieves this through a combination of high-speed digital processing and specialized algorithms tailored specifically for hydraulic physics, such as non-linear flow characteristics and fluid compressibility.

This controller is a "bus-compatible" unit, meaning it is designed to sit at the heart of an automated system, communicating effortlessly with higher-level PLCs while maintaining local deterministic control over the hydraulic actuator. The single-axis design of the VT-HNC100-1-23 makes it an efficient and focused solution for independent machine movements.

Functional Characteristics and Design Intelligence

Precision Multi-Mode Control

The VT-HNC100-1-23/W-08-S-0 is not limited to simple position control. It features multi-functional control loops that can be switched "on the fly." A common application involves a hydraulic cylinder moving rapidly into position (position control), transitioning smoothly to a controlled press (force/pressure control), and then maintaining a specific velocity during a machining stroke. The HNC100 manages these transitions with internal logic that prevents pressure spikes and mechanical jars, ensuring the longevity of the hydraulic system.

SSI and Incremental Feedback Compatibility

To achieve micron-level accuracy, the controller supports high-resolution feedback systems. The integrated SSI (Synchronous Serial Interface) allows for the use of absolute linear transducers, which provide position data immediately upon power-up without the need for a homing cycle. Additionally, the support for incremental encoders allows for high-frequency velocity monitoring, essential for maintaining stable motion at very low speeds.

Optimized for Hydraulic Physics

Unlike general-purpose PLCs, the Rexroth VT-HNC100 contains built-in compensation for hydraulic variables. It includes pre-defined tables for valve linearization, accounting for the fact that hydraulic fluid flow through a proportional valve is not perfectly linear. Furthermore, it automatically compensates for the "area ratio" of differential cylinders (the difference in surface area between the piston side and the rod side), ensuring that force calculations and velocity controls are accurate in both directions of travel.

Key Industry Applications

The versatility of the VT-HNC100-1-23/W-08-S-0 makes it a preferred choice for precision-focused industries:

• Plastic Injection Molding: Precise control of the injection stroke and clamping force to ensure part quality and consistency.

• Metal Forming: Managing the complex pressure and position profiles required in hydraulic presses and bending machines.

• Woodworking: Controlling high-speed axes in CNC routers and saws where hydraulic power is needed for heavy cutting forces.

• Metallurgy: Operating ladle tilting or roller adjustment axes in steel mills where heat and EMI are prevalent.

Configuration and Software Environment

System setup is performed via the WIN-HNC software. This environment allows engineers to program complex motion sequences using a simplified command language. The software also includes a "scope" function, which allows for real-time monitoring of command vs. actual values. This is an invaluable tool for PID tuning, allowing technicians to visualize the dampening and response times of the hydraulic axis and eliminate oscillation.

The controller's hardware is designed for long-term reliability. Its internal 32-bit architecture ensures that even complex mathematical calculations are performed within the millisecond cycle times required for high-dynamic hydraulic valves. The robust 8 digital inputs and 8 digital outputs (W-08) provide the necessary local I/O for limit switches, sensors, and status lamps, reducing the burden on the central PLC.