The work section is comprised of two independent spools that act as a pair working to control double acting services, or alternatively as single spools controlling a single acting service (2 single acting services can be controlled from any work section).
Demands to each work section are transmitted over a CAN bus and power is provided to each work section via a single daisy chain cable arrangement. Each work section has a single pilot valve comprised of on-board electronics, embedded sensors, and two independent 3 position 4 way pilot spools driven by a low power embedded micro controller.
The independent pilot spools control the mainstage spools. Closed loop control of each work section is achieved locally by leveraging the on-board electronics and sensors.
Each mainstage spool has its own position sensor enabling closed loop position control of the mainstage spool.
Further, a pressure sensor is located in each work port, pressure line, load sense line and tank line.
With the upstream and downstream pressure information known at any time, flow delivered to the service can be controlled by moving the spools to create the appropriate orifice area for the desired flow rate.
Features
Pressure compensated meter-in and meter-out control
Precise close loop control
Sub-micron hysteresis
High valve responsiveness
Flow sharing - pre and post compensation capabilities
Flexibility in configuration with easily changed parameters
Command factory-calibrated flow from either work port
Easy to use CAN communication with the valve
Reduced load on the vehicle CAN bus
Advanced diagnostics for improved reliability and productivity
Hose burst detection
Limp mode
Inlet, tank, load sense, and work port pressures, spool position, consumed flow and oil temperature
Platform can support future software development for future product development
Reliable performance across a broad temperature range
Additional features and benefits with CMA work section
Independent metering control
Advanced force and flow, control modes
Intellifloat and boom stability control capabilities
Command factory-calibrated pressure from either work port