Heidenhain: Interface Electronics (IDP 100)

Interface electronics from HEIDENHAIN adapt the encoder signals to the interface of the subsequent electronics. They are used when the subsequent electronics cannot directly process the output signals from HEIDENHAIN encoders, or if additional interpolation of the signals is necessary.

HEIDENHAIN interface electronics are available in various mechanical designs.

IDP 101/IDP 181/IDP 182 Interpolation and Digitizing Electronics

HEIDENHAIN linear, rotary and angle encoders operate on the principle of photo-electrically scanning very fi ne gratings. These encoders normally produce sinusoidal scanning signals with levels of approximately 11 µAPP (current signals) or approx. 1 VPP (voltage signals). The subsequent electronics first interpolate the scanning signals and then convert them into square-wave pulses (digitizing). The interpolation and digitizing circuitry is either integrated in the NC control (e.g. a HEIDENHAIN TNC) or in the numerical display (e.g. ND or POSITIP from HEIDENHAIN), or is available as a separate unit: IDP 18x (for voltage signals A, B and R) or IDP 101 (for current signals I1, I2 and I0).

The IDP provides two square-wave pulse trains (Ua1 and Ua2) and a reference pulse Ua0 as output signals. Within one signal period, each of the four signal edges of Ua1 and Ua2 can serve as a counting pulse. The distance between two subsequent edges of Ua1 and Ua2 is one measuring step. After 5-fold interpolation, for example, this distance is 1/20th of a grating period.

The adjustment to the subsequent electronics is quite easy. The interpolation, edge separation and reference pulse width are adjusted using PCB switches. Failure indication consists of a separate fault detection signal, or in addition, a switch to high impedance in the outputs Ua1 and Ua2.