Hydraulic Valve Adds Configurable Dual-Loop Control

Parker Hannifin has expanded its fourth-generation DFplus valve platform with the introduction of the D-version variant, a direct-operated valve designed to support customer-specific, closed-loop functions. Engineered for applications requiring high dynamic response and precise calibration, the hardware serves as a central hub within the digital supply chain of industrial machinery, regulating variables such as volume flow in pumps and real-time pressure adjustments. The technology is optimized for deployment in demanding manufacturing environments, including pressure management systems in paper production machinery and high-speed hydraulic presses.

Integrated Dual-Loop Architecture and Sensor Interfaces
Standard proportional valves typically rely on a single internal control loop to manage spool position based on an external command signal. The D-version architecture alters this framework by integrating a second, freely parameterizable control loop directly into the onboard valve electronics. This dual-loop topology allows the valve to simultaneously govern its internal mechanics and an external process variable, such as system pressure or cylinder displacement.

To facilitate this secondary loop, the valve electronics feature a high-resolution sensor signal interface accessible via an integrated M12 connection socket. Analog pressure or displacement measurement sensors connect directly to this port, drawing their operational power directly from the valve electronics. This setup eliminates the need for separate external sensor power supplies and reduces intermediate cabling, minimizing signal attenuation and electrical noise interference in the data ecosystem. The system supports selectable setpoint configurations, allowing operators to input analog setpoint signals tailored to specific process requirements.

Digital Configuration and Communication Protocols
The D-version option is available across the D1FP, D3FP, and D30FP proportional valve series. Configuration, parameterization, and diagnostics of the secondary control loop are handled via digital interfaces rather than manual hardware adjustments. Technicians can configure the loop dynamics using Parker ProPXD parameterization software or via a standardized IO-Link digital interface.

The hardware utilizes an IO-Link Class A connection as standard for data transmission and power. For applications requiring advanced control flexibility, an optional IO-Link Class B variant is available, which provides a switchable controller architecture to alter control strategies during operation based on real-time production demands.

According to the Hydraulic Valve Systems Division Europe, these valves offer a cost-effective solution for high-dynamic, closed loop-controlled applications by consolidating control processing and sensor power distribution directly onto the valve assembly.

Additional Context
This section details technical specifications and competitive benchmarking not included in the original news release.

The primary technical differentiator of the D-version valve is its decentralized control architecture. Conventional high-dynamic valves, such as the Bosch Rexroth 4RPWE or the Moog D633, process secondary process loops (like pressure or position) within a central Programmable Logic Controller (PLC) or an external motion controller. Processing the secondary loop on the valve electronics shortens the control loop cycle time, reducing propagation delay and improving the dynamic stiffness of the system during rapid pressure drops or high-speed press cycles.

Furthermore, while competitive models use industrial Ethernet protocols for high-speed fieldbus communication, they typically treat the valve as an execution device rather than a sensor aggregator. The inclusion of an automated sensor power feed and an integrated feedback interface within an IO-Link Class B environment allows the D-version to act as an edge node, reducing the I/O footprint required in the main electrical cabinet.

Edited by Aishwarya Mambet, Induportals Editor, with AI assistance.

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