Linear encoders, RF20X Series - RIFTEK - #5

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Absolute linear encoders, RF25X RF25X [Revision 1.1] 10th October 2010 RIFTEK 5 5. Example of item designation when ordering RF25Õ.Ð-L-D-UART-AN-IN-LOUT–ÑÑ-Ì Symbol Description Õ Model (1 or 6) Ð Increased accuracy L Measurement range, mm D Resolution, um UART Type of the serial interface (RS232 or RS485) AN Attribute showing the presence of Current Loop (I) or Voltage (U) output IN Trigger input (input of synchronization) LOUT Attribute showing the presence of 2 logical outputs ÑÑ Cable gland - CG or connector - CC Ì Cable length, m Example: RF256-55-0.1-232-I-IN-ÑÑ-3, RF256 sensor with standard accuracy; 55 mm measurement range; 0,1 um resolution; serial port – RS232; 4…20 mA analog output; IN – synchronization input presents; connector; 3 m cable length. 6. Structure and operating principle Operation of the sensors is based on the principle of photoelectric scanning of special scale, connected with a measurement tip of the sensor. Radiation of a LED 1 is collimated by a lens 2 and is directed on a scale 3. The image of area of the scale is examined by CMOS array 4 and is analyzed by signal processor which calculates position of the scale. As compared with incremental sensors, absolute sensors have a number of advantages: the absolute position of the measurement tip is determined immediately after power is on and the necessity of search of the reference mark is excluded. Also excluded is the probability of accumulation or loss of count pulse signals in case of impacts, vibrations and reverse motion. Figure 1