For high quality speed control, Heidenhain Corporation recently introduced new low profile incremental rotary encoders with block commutation tracks, especially suitable for use in small-dimensioned servo motors. These new rotary encoders of the 1000 and 1100 series come equipped with an industry-standard 35 mm housing diameter. These encoders distinguish themselves not only by their short overall length but also by their modern opto-ASIC based photoelectric scanning with integrated interpolation. Thanks to the electrical output at TTL levels with differential signals, these encoders can be connected to almost all standard subsequent electronics for control of digitally controlled servo motors (up to edge lengths of 40 mm and 55 mm), and are useful in various applications in the automation industry. Currently available, the Heidenhain 1023 encoder has an overall length of 35.2 mm max and an IP 64 rating, making it especially useful in hazardous environments; the Heidenhain 1123 encoder has an overall length of 30.3 mm max and an IP 0 for general use. Both encoders have mounted stator couplings and blind hollow shafts. Choice of appropriate commutation signals is available to the buyer as the amount depends upon the number of poles of the motor to be controlled.