The ADN 402 has been developed as a digital controller incorporating a valve amplifier for proportional valves with two magnets. The valve output stages function with fast de-excitation, with the result that the magnet current is adjusted to 0 in approx. 3–4ms.
Thanks to its high-speed output stages, the ADN 402 is extremely suitable for control tasks in the 0–30Hz frequency range, and the module has therefore been equipped with a triple-controller cascade.
The input sensor system is equipped with interchangeable sensor modules, signifying that the module can be operated using widely used input signals, such as 4–20mA or +/–10V, or other similar signals. The sensor input modules are equipped with a second-order low-pass filter. Phase shift at 30Hz is approx. 3°, and damping approx. 45dB at 10kHz. The setpoint can be specified either analog or digital using the CAN bus.
The direction line of action (sign) of the individual sensor modules can be set via the ADN configurator. This permits start-up of the complete system at rational cost.
The external sensors can be supplied with 24V/0.5A DC from the unit. A PTC thermistor assures full (thermistor-type) protection against external short-circuits. Alarm signalization is effected via a separate output, which can be loaded to 24V/100mA.
The ADN 402 is equipped with six opto-decoupled inputs. These are, in standard configuration, an Enable input, a Ramp OFF input, and four setpoint inputs. Other input configurations are also possible in special cases. The ramps are assigned to the four internal setpoints and can be set from 0.01s to 30s in increments of 10ms. The module can, in addition, also be externally actuated by means of an analog input. The three controllers are P, I and DT1 controllers, with a sample time of approx. 0.1ms. An internal function generator, the frequency of which can be selected between 0.1 and 50Hz, is available for controller optimization. The generator supplies sinusoidal, triangular and square waves. Amplitude and offset can be entered at +/–10V.
All settings on the ADN 402 can be effected using the ADN configurator via an RS232 interface connected to a PC or laptop computer.
The input software ADN configurator is available via the Internet.
The ADN 402 can, of course, also be used for applications with a single magnet in which a choke or a pressure adjustment valve is used. Only the values for the B magnet must then be set to 0 in the ADN configurator.