AX021900 8 Input, 5 Output Valve Controller

8 Inputs, 5 Outputs, 1-2.5A Output Rating 

The 8 Input, 5 Output Valve Controller (8i5o) is designed for versatile control of up to four proportional outputs to directly drive coils or other loads. Its flexible circuit design gives the user a wide range of configurable input or output types. The sophisticated control algorithms allow the user to program the controller for a wide range of applications without the need for custom software.

The controller has six fully programmable universal inputs that can be setup to read: voltage; current; resistive; frequency; or digital input signals. For added flexibility, it also has a magnetic sensor circuit that can read AC signals and convert them into a frequency (RPM) pickup. Lastly, there is an eighth digital input that can be used for global enable/disable or overrides of one or all of the outputs.

There are four universal outputs that can be setup to drive: proportional current (up to 2.5A each); hotshot digital current; proportional voltage (up to supply); proportional PWM; or straight on/off digital loads. For applications requiring a fifth digital output, there is also one high-side (sourcing) output for up to a 2.5A digital load.

The 8i5o valve controller is highly programmable and allows the user to configure it for their application. Its sophisticated control algorithms allow for open or closed loop drive of the proportional outputs. It can be operated as either a self-contained control system, driving the outputs directly from the on-board inputs, and/or it can be integrated into a CAN J1939 network of controllers. All I/O and logical function blocks on the unit are inherently independent from one another, but can be programmed to interact in a large number of ways. Refer to the block diagram, Figure 1A, for the hardware features. Figure 1B shows the logical function blocks (software) available on the 8i5o.

The 8i5o has a number of built-in protection features that can shut off the outputs in adverse conditions. They include hardware shutoffs to protect the circuits from being damaged as well as software shutdown features that can be enabled in safety critical systems.

The various function blocks supported by the 8i5o are outlined below. All setpoints are user configurable over the CAN port using the Electronic Assistant® and an Axiomatic USB-CAN converter.


The controller is designed for harsh operating environments. Typical applications can include:

  • Industrial, off-highway and marine applications - control of hydraulic proportional poppet or spool valves
  • Closed loop control of hydraulic valves
  • Interface with a diesel engine’s electronic control module PWM signal to drive accessories
  • Transmission controls
  • Fan drive controls (on request)
  • Vehicle traction control (on request)


  • Inputs:
    • 6 universal analog signal inputs (current, voltage, resistive, frequency, digital or PWM)
    • 1 digital input for enable/disable functionality
    • 1 magnetic pickup sensor input (RPM)
  • Outputs:
    • 4 proportional or on/off valve drivers up to 2.5 A
    • Open or closed loop (PID) drive is user configurable.
    • 1 digital output up to 2.5A
    • Fully protected
  • 1 CAN (SAE J1939) port
  • CANopen® module available on request
  • PID control logic is user configurable
  • Time delays can be programmed using the Look Up Tables
  • Flexible and user programmable functionality for diverse applications using the PC-based Electronic Assistant® together with an Axiomatic USB-CAN converter
  • 12V or 24Vdc nominal
  • Rugged IP67 protection for harsh environments
  • Vibration compliance for mobile equipment