Manual optoNCDT 1402 - Micro-Epsilon

Operation6.5 TimingThe controller operates internally with real time cycles in a pipeline mode:1. Exposure: Charging the image detector in the receiver (measurement).2. Reading: Reading out of the imaging device and converting into digital data.3. Computation: Measurement computation.4. Controlling.The output through the analog and digital interface starts with the beginning of every new cycle. The analog value and digital switchoutputs are updated immediately and the digital output starts with the start bit.Each cycle takes 666 μs at a measuring rate of 1.5 kHz. The measured value N is available after each cycle with a constant lag of fourcycles in respect to the real time event. The delay between the input reaction and the signal output is therefore 2 up to 2.7 ms. Theprocessing of the cycles occurs sequentially in time and parallel in space (pipelining, see Fig. 17). This guarantees a true constant realtime data stream.Cycle 1. 2. 3. 4. 5. 6.Time max. 5 s 666 µs 1322 µs 1998 µs 2664 µs 3330 µs 3996 µsInitialisationincluding theoutput of theinfo stringExposure N Reading N Computation N Controlling N Output NExposure N+1 Reading N+1 Computation N+1 Controlling N+1 Output N+1First exposure after power up of the sensorExposure N+2 Reading N+2 Computation N+2 Controlling N+2 ...Exposure N+3 Reading N+3 Computation N+3 ...Fig. 17 Sensor timing at a measurement rate of 1.5 kHziThe sensor needs time until measuring values are available according to the set averaging number N.Exposure N+4 Reading N+4 ...... ...optoNCDT 1402Page 35