The POSITAL IXARC OCD-DPC1B-1213-B15S-H3P Optical Profibus DP encoder provides 13 bit resolution and 12 bit resolution along with excellent dynamic response and is suitable for use in areas with high magnetic fields A Profibus DP interface helps to simplify installation and offers the following programmable features: Resolution, gearing factor (physical resolution) , velocity scaling + filter, preset (zero point), counting direction, limit switches , node number, teach-in, diagnosis. Aluminum flange, Steel housing and void temperature range provide IP66/IP67 environmental protection. Since the rotation of the code discs is an entirely mechanical process, there is no risk of these devices losing track of their absolute position due to a temporary loss of instrument power. No backup batteries are required! A key component of optical rotary encoders is a code disk mounted on the encoder shaft. This disk is made of a transparent material that has a concentric pattern of transparent and opaque areas. Infrared light from an LED shines through the code disk, onto an array of photoreceptors. As the shaft turns, a unique combination of photoreceptors are illuminated or blocked from light by the pattern on the disk. For multiturn models, there is an additional set of code discs arranged in a gear train. As the main encoder shaft rotates, these discs are geared together to turn like the wheels of an odometer. The rotational position of each disc is monitored optically and the output is a count of the net number of rotations of the encoder shaft.