The design objective was to develop a module, that combines set point generator, ramp generator, controller and monitoring devices in a single unit. In addition, an analogue output stage with high dynamic performance has been included for special applications, so that the controller can be used for proportional valves without integral drive amplifier. For such applications, the inclusion of the valve electronics in the AN307 controller represents a considerable cost saving. A 12 bit D/A converter is provided for the control of servo, regulating or proportional valves with integral electronics, so that the entire spectrum of hydraulic positioning can be controlled.
The set point generator permits the input of a maximum of 31 binary coded set points. The set point can also be input externally in analogue form. The ramp generator also permits the input of 31 different ramps in association with the 31 digital set points or the analogue set point. The ramps can be in linear form, or in case of the digital set points in sine-square form. The ramp times can be set from 10ms to 100sec in 9999 steps.
The controller is divided into 1, 2 or 3 blocks depending on the application. The output of each controller block becomes the command variable for the next block (cascade controller). Two controller blocks are designed as state controllers with feed-forward and provide good results even with critical drives. The use of a 32 bit processor system achieves short cycle times, allowing drives with high dynamic demands to be controlled.
The sensor system is of universal design, so that the widest variety of sensors can be evaluated by exchanging a sensor plug-in module (e.g. 4…20mA, ±10V, 7.5V±4V). In addition, an integral medium-frequency generator permits the connection of an inductive displacement sensor.
The AN307 controller is equipped with two status signals. Status 1 displays the fault messages and status 2 indicates that the actual value is equal to the set point. The fault is displayed in such a manner that the cause of the fault can be easily identified.