REXROTH VT-HNC100-1-23/M-08-P-0 Digital Axis Control

I. Overview

• Receiving control commands from the main controller via 2 analog inputs (AI) (e.g., 0-10V spool displacement command with 16-bit resolution);

• Sending drive current signals (±100mA, accuracy ±0.1% FS) to electro-hydraulic valves via 2 analog outputs (AO);

• Collecting the actual spool position (sampling rate 1kHz) through 2 differential feedback inputs (from LVDT sensors) to achieve closed-loop control of the spool position;

• Incorporating a built-in Digital Signal Processor (DSP) that supports PID + feedforward composite control algorithms to dynamically compensate for changes in hydraulic oil viscosity (e.g., viscosity fluctuations caused by temperature);

• Featuring signal filtering (adjustable low-pass filter cutoff frequency: 10Hz~1kHz) and fault self-diagnosis (output short circuit/overcurrent, sensor signal loss);

• Supporting parameter configuration and status monitoring via Rexroth IndraWorks Engineering software;

• Boasting an IP65 protection rating, making it suitable for oily and dusty environments of hydraulic equipment.

• I/O Channels and Signal Processing: 2 AI channels (0-10V/±10V, 16-bit resolution, input impedance ≥1MΩ), 2 AO channels (±100mA current output, accuracy ±0.1% FS, load resistance 0-100Ω), 2 differential feedback inputs (LVDT sensor signal, 0-5V, sampling rate 1kHz); All analog channels are equipped with photoelectric isolation (isolation voltage ≥2.5kVrms) and electromagnetic shielding (metal housing + double-layer shielded wires) to avoid electromagnetic interference from the hydraulic system (e.g., hydraulic pump motor); The output channels have overcurrent protection (maximum current 150mA) and short-circuit protection (response time ≤10μs);

• Core Control Unit: Built-in 32-bit floating-point DSP (TI TMS320F28335, operating rate 150MHz) that supports parallel processing of closed-loop control algorithms for 2 electro-hydraulic valves; Equipped with 64MB Flash (for storing control parameters and firmware) and 32MB RAM (for caching real-time feedback data), supporting online firmware upgrades (without interrupting equipment operation); Supports multiple control modes (position control, speed control, pressure control), which can be switched via software;

• Housing and Protection: Adopts a die-cast aluminum alloy housing (with oil-resistant and anti-corrosion coating), with dimensions of 140mm×80mm×50mm (length × width × height), supporting 35mm standard DIN rail mounting and panel mounting; IP65 protection rating (dust-proof and jet water-proof), suitable for oily and misty environments of hydraulic stations; Operating temperature: -25℃~70℃, storage temperature: -40℃~85℃, relative humidity: 5%~95% (no condensation);

• Safety and Redundancy Design: Supports dual power input (24V DC±20%, compatible with 12V DC/48V DC), with automatic switching in case of a single power failure to avoid power supply interruption; Key circuits (such as DSP and power amplification circuits) adopt dual-design to prevent electro-hydraulic valve out-of-control caused by single-point faults; Complies with CE, UL, and CSA safety certifications, meeting the safety requirements of industrial equipment.

II. Technical Parameters

1. I/O Channel and Signal Parameters

2. Control Performance Parameters

3. Environmental and Reliability Parameters

III. Functional Features

1. Micron-Level Closed-Loop Control Accuracy for High-End Hydraulic Equipment

• 16-Bit High-Resolution Signal Processing: The 16-bit resolution of AI input and ±0.1% FS accuracy of AO output, combined with LVDT feedback at a sampling rate of 1kHz, reduce the spool position control error from ±20μm (traditional open-loop) to ±3μm. In a precision injection molding machine, the dimensional tolerance of injection-molded parts is reduced by 50%, and the scrap rate drops from 8% to 2%;

• High-Frequency Response and Dynamic Compensation: With the 150MHz DSP computing capability and 100Hz bandwidth, the step response time of the electro-hydraulic valve is ≤1ms. Meanwhile, feedforward control is used to compensate for changes in hydraulic oil viscosity (e.g., when the temperature rises from 25℃ to 50℃, the viscosity decreases by 30%, and the module adjusts the drive current in real time). In a cold rolling mill, the thickness fluctuation of steel plates is reduced from ±0.02mm to ±0.01mm;

• Multi-Mode Precision Control: It supports switching between position/speed/pressure control modes. An aerospace test bench switches between "position control mode (testing spool stroke)" and "pressure control mode (testing hydraulic system pressure resistance)" via software without replacing the module, improving test efficiency by 40%.

2. Strong Anti-Interference and Protection for Harsh Hydraulic Environments

• IP65 High Protection Rating: The die-cast aluminum alloy housing with sealing rubber strips is oil-resistant and jet water-proof. In a hydraulic station (oily environment), the module operates continuously for 2 years without internal oil intrusion, no corrosion on the circuit board, and no attenuation in output accuracy;

• Electromagnetic Shielding and Isolation: The metal housing and 2.5kVrms photoelectric isolation ensure that the AO output current fluctuation is ≤0.1% FS near a 10kW hydraulic pump motor (with 50V/m electromagnetic radiation), preventing misoperation of the electro-hydraulic valve caused by false signals;

• Anti-Vibration and Anti-Impact: With 5g vibration resistance and 20g impact resistance, the module remains free from loosening and signal interruption in a heavy-duty truck hydraulic test bench (with 3g vibration acceleration), ensuring continuous and reliable test data.

3. High Reliability and Redundancy Design for Uninterrupted Equipment Operation

• Dual Power Redundancy: Dual 24V DC power input supports the "main-standby" mode. In the hydraulic system of a steel mill's rolling mill, when the main power fails, it switches to the standby power within 1ms, preventing the electro-hydraulic valve from out-of-control due to power loss and avoiding steel plate scrapping (single loss exceeding 100,000 yuan);

• Fault Self-Diagnosis and Protection: It real-time monitors faults such as output short circuit and feedback loss, and immediately cuts off the output and triggers an alarm when a fault occurs. In an injection molding machine, when the electro-hydraulic valve coil is short-circuited, the module cuts off the current within 0.5ms, avoiding damage to the module and valve group (maintenance cost exceeding 5,000 yuan);

• Long-Life Components: It uses oil-resistant and high-temperature-resistant components (such as fluororubber seals and 125℃ temperature-resistant capacitors). In the environment of -25℃~70℃, the MTBF is ≥30,000 hours, and the average annual downtime is ≤2.92 hours, which is far lower than the ≤8 hours/year downtime requirement for hydraulic equipment.