Square wave encoders are widely used in industry and in the measurement sector. They allow to read the position of a rotating axis with good resolution while requiring relatively simple circuitry. In the case of linear axes, optical scales with square wave output are used instead. In coordinate measuring machines (CMMs) where high resolution is not required, optical encoders with square wave output are employed. With this kind of device, less expensive than their sine wave counterpart, resolutions of up to 20000 pulses per rotation can be reached.

CMMs allow the measure of points in space and the calculation of the relative cartesin coordinates X,Y,Z using an appropriate mathematical model. In the automotive sector, for example, using a specialized CMM and software, it is possible to make complex measurements on the chassis, shock absorbers and many other parts of the vehicle, comparing then the measured values with the nominal positions provided by the vehicle's constructor.

Sinai Srl has been designing and producing boards for reading square wave encoders, especially for use in the CMM sector. The use of off-the-shelf square wave encoders and Sinai electronics allowed our customers to build accurate and reliable CMMs. A typical system is composed of an "Interface" board and several "Encoder" boards with other, optional, boards for auxiliary functions. The boards are connected to each other via a RS485 communication channel, while communicating with a computer using an USB port or Bluetooth technology in the case of portable, wireless CMMs.