The ADN 404 has been developed as a digital controller with a valve amplifier for actuation of a servo-valve. The output stage is suitable in four ranges for +/– 20mA to 200mA valves.
The ADN 404 is extremely suitable for use with high-speed servo-valves for control functions in the 0–150Hz frequency range. The ADN 404 has been equipped with a triple-controller cascade, in order to permit a large number of applications. A facility for limitation of servo-valve deflection has been implemented, in order to improve matching of valves to load conditions.
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. A medium-frequency generator with a demodulator is available for operation with inductive position encoders. The sensor input modules are equipped with a second-order low-pass filter. Phase shift at 150Hz is 13°, damping at 10kHz is approx. 45dB.
The line of action (sign) of the individual sensor modules can be selected using the ADN configurator. This permits rapid start-up of systems at rational cost.
The external sensors can be supplied with 24V DC from the device. A PTC thermistor assures full thermistor-type protection against external short-circuit.
Alarms are issued via a separate output which can be loaded to 24V/100mA.
The ADN 404 is equipped with six opto-decoupled inputs. These are, in standard configuration, one Enable input, one 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 or via the CAN bus. 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 provided for controller optimization. The generator supplies sinusoidal, triangular and square waves. Amplitude and offset can be selected up to +/–10V.
All settings on the ADN 404 are made using the ADN configurator via an RS232 interface linked to a PC or laptop computer.
The input software ADN configurator is available free-of-charge on the Internet.