Rexroth Bosch Group HNC100 Hydraulic Shaft Control

HNC100 Digital Axis Controller: Practical Analysis from Engineering Configuration to Hydraulic Closed Loop Control

In the field of hydraulic servo control, precise, reliable, and flexible motion control is the core of improving the performance of mechanical equipment. For applications with strict requirements such as plastic processing machinery, press machines, specialized machine tools, and even rail vehicles, a shaft control system that can cope with complex working conditions, provide powerful programming capabilities, and integrate multiple controller types is crucial. Bosch Rexroth's VT-HNC100 digital axis controller was born for this purpose. This article will deeply analyze the hardware characteristics, software configuration process, core control algorithms, NC programming practices, and key fault diagnosis methods of HNC100 from the perspective of an engineering technician, aiming to provide a comprehensive application guide for engineers engaged in hydraulic system integration, debugging, and maintenance.

System Overview: Why is HNC100 suitable for harsh industrial environments?

HNC100 is not a simple control card, but a complete programmable NC control solution optimized for closed-loop control of hydraulic shafts, and can also be used to control electrical drives. Its original design intention was to cope with harsh industrial environments. According to its technical documentation, HNC100 meets high standards in terms of anti-interference ability (electromagnetic compatibility), mechanical resistance to vibration and impact, and adaptability to climate and environment, and complies with EU directives (CE mark). This means that whether it is an injection molding workshop filled with electromagnetic noise or a press with continuous vibration, the HNC100 can operate stably.

From a hardware architecture perspective, the HNC100 is based on a 16/32-bit MC68376 processor, equipped with 1 MB Flash EPROM, 8 KB EEPROM, and 256 KB RAM, providing ample resources for complex control algorithms and user programs. Its power supply voltage range is 18 to 36 VDC, with a power consumption of only 8W (excluding external sensors and actuators), reflecting the energy efficiency design of industrial grade products.

For engineers, the value of a controller is primarily reflected in its ability to interact with the external world. HNC100 provides rich process interfaces:

Digital I/O: 8, 16, or 24 point digital input and output can be selected according to the model, with clear logic levels (high level ≥ 10V to Uo, low level ≤ 5V), maximum output current of 50mA, and can directly drive small relays or indicator lights.

Analog input: includes multiple differential voltage inputs (± 10V, 16 bit resolution) and current inputs (4-20mA), used to connect various sensors such as pressure sensors, displacement sensors (non digital), etc. It is worth mentioning that it provides a high-precision ± 10V reference voltage internally to provide excitation for external sensors.

Analog output: Provides voltage output (± 10V) and current output for directly driving integrated electronic devices of servo valves and proportional valves.

Position sensor interface: Supports incremental encoders (TTL, up to 250kHz), SSI absolute encoders (Gray code, up to 28 bit data width), and inductive position sensors (such as LVDT). In addition, the EnDat interface is also being prepared. This provides great flexibility for design selection.

Software Defined Control: WIN-PED and the Birth of Engineering Projects

The soul of HNC100 lies in its concept of "software defined control". All control logic, motion curves, and parameter settings are not fixed, but are generated into a "Project" through a PC software called "WIN-PED" and downloaded into the controller. This process is very clear and divided into five steps, similar to writing a PLC program:

Define tasks and sequence chart: Engineers first need to clarify what tasks HNC100 needs to complete and record them in the form of a sequence chart. This includes defining the meaning of each digital input/output and the various parameters to be used.

Write NC program: Convert each functional step in the sequence diagram into a series of NC commands. HNC100 uses an NC language similar to G-code, which supports subroutine techniques and conditional jumps, providing powerful support for programming complex action sequences.

Configuring machine data: This step is the "handshake" between hardware and software. Engineers need to select the actual encoder type (incremental, SSI, or inductive) and configure the controller type (position, pressure, speed) in WIN-PED, and set relevant parameters.

Download project: Send complete project data to the flash memory of HNC100 via RS232 serial interface (standard configuration, 9.6 kBaud).

On site optimization: Execute programs on the machine, monitor process data in real-time, adjust parameters, optimize motion trajectories and control effects through the online function of WIN-PED or the handheld operation box BB-3.

The WIN-PED software itself is the core tool of this process. Its functionality goes far beyond just a text editor. It includes: an NC editor with syntax checking and compiler; A dialogue window for setting machine data online or offline; A polygon editor used for graphically defining special motion curves (such as cam curves); And powerful diagnostic tools that can simultaneously record and graphically display up to four process variables (such as position command value, actual position, tracking error, pressure feedback), and support trigger condition settings. This is extremely helpful for analyzing and optimizing dynamic responses.