SLYY211 October   2021 TMS320F2800132 , TMS320F2800133 , TMS320F2800135 , TMS320F2800137 , TMS320F2800152-Q1 , TMS320F2800153-Q1 , TMS320F2800154-Q1 , TMS320F2800155 , TMS320F2800155-Q1 , TMS320F2800156-Q1 , TMS320F2800157 , TMS320F2800157-Q1 , TMS320F280021 , TMS320F280021-Q1 , TMS320F280023 , TMS320F280023-Q1 , TMS320F280023C , TMS320F280025 , TMS320F280025-Q1 , TMS320F280025C , TMS320F280025C-Q1 , TMS320F280033 , TMS320F280034 , TMS320F280034-Q1 , TMS320F280036-Q1 , TMS320F280036C-Q1 , TMS320F280037 , TMS320F280037-Q1 , TMS320F280037C , TMS320F280037C-Q1 , TMS320F280038-Q1 , TMS320F280038C-Q1 , TMS320F280039 , TMS320F280039-Q1 , TMS320F280039C , TMS320F280039C-Q1 , TMS320F280040-Q1 , TMS320F280040C-Q1 , TMS320F280041 , TMS320F280041-Q1 , TMS320F280041C , TMS320F280041C-Q1 , TMS320F280045 , TMS320F280048-Q1 , TMS320F280048C-Q1 , TMS320F280049 , TMS320F280049-Q1 , TMS320F280049C , TMS320F280049C-Q1 , TMS320F28075 , TMS320F28075-Q1 , TMS320F28076 , TMS320F28374D , TMS320F28374S , TMS320F28375D , TMS320F28375S , TMS320F28375S-Q1 , TMS320F28376D , TMS320F28376S , TMS320F28377D , TMS320F28377D-EP , TMS320F28377D-Q1 , TMS320F28377S , TMS320F28377S-Q1 , TMS320F28378D , TMS320F28378S , TMS320F28379D , TMS320F28379D-Q1 , TMS320F28379S

 

  1. 1 Message from the editors
  2. 2 System Design
    1. 2.1 Control
      1. 2.1.1 Open loop versus closed loop
    2. 2.2 Feedback control
      1. 2.2.1 Error ratio
    3. 2.3 Dynamic systems
      1. 2.3.1 First order system
      2. 2.3.2 Second order system
    4. 2.4 System stability
      1. 2.4.1 Gain margin
      2. 2.4.2 Phase margin
    5. 2.5 Timing requirements
      1. 2.5.1 Peak/rise time
      2. 2.5.2 Settling time
      3. 2.5.3 Overshoot
      4. 2.5.4 Damping
      5. 2.5.5 Delay
    6. 2.6 Discrete Time Domain
    7. 2.7 Filters
      1. 2.7.1 Filter Types
      2. 2.7.2 Filter Orders
    8. 2.8 Notes
  3. 3 Controllers
    1. 3.1 Linear PID
    2. 3.2 Linear PI
    3. 3.3 Nonlinear PID
    4. 3.4 2P2Z
    5. 3.5 3P3Z
    6. 3.6 Direct form controllers
      1. 3.6.1 DF11
      2. 3.6.2 DF13
      3. 3.6.3 DF22
      4. 3.6.4 DF23
    7. 3.7 Notes
  4. 4 ADC
    1. 4.1 ADC definitions
    2. 4.2 ADC resolution
      1. 4.2.1 ADC resolution for unipolar
      2. 4.2.2 ADC resolution for differential signals
      3. 4.2.3 Resolution voltage vs. full-scale range
    3. 4.3 Quantization error of ADC
    4. 4.4 Total harmonic distortion (THD)
      1. 4.4.1 Total harmonic distortion (VRMS)
      2. 4.4.2 Total harmonic distortion (dBc)
    5. 4.5 AC signals
    6. 4.6 DC signals
    7. 4.7 Settling time and conversion accuracy
    8. 4.8 ADC system noise
    9. 4.9 Notes
  5. 5 Comparator
    1. 5.1 Basic operation
    2. 5.2 Offset and hysteresis
    3. 5.3 Propagation delay
    4. 5.4 Notes
  6. 6 Processing
    1. 6.1 Data representation
    2. 6.2 Central processing unit
      1. 6.2.1 CPU basics
      2. 6.2.2 CPU pipeline
      3. 6.2.3 Characteristics of a real-time processor
      4. 6.2.4 Signal chain
    3. 6.3 Memory
    4. 6.4 Direct memory access (DMA)
    5. 6.5 Interrupts
    6. 6.6 Co-processors and accelerators
    7. 6.7 Notes
  7. 7 Encoders
    1. 7.1 Encoder definitions
    2. 7.2 Types of encoders
    3. 7.3 Description of encoders
      1. 7.3.1 Linear encoders
      2. 7.3.2 Rotary encoders
      3. 7.3.3 Position encoders
      4. 7.3.4 Optical encoders
    4. 7.4 Absolute Vs incremental encoders
      1. 7.4.1 Absolute rotary encoders
      2. 7.4.2 Incremental encoders
    5. 7.5 Notes
  8. 8 Pulse width modulation (PWM)
    1. 8.1 PWM definitions
    2. 8.2 Duty cycle
    3. 8.3 Resolution
    4. 8.4 Deadband
    5. 8.5 Notes
  9. 9 DAC
    1. 9.1 DAC definitions
    2. 9.2 DAC error
      1. 9.2.1 DAC offset error
      2. 9.2.2 DAC gain error
      3. 9.2.3 DAC zero-code error
      4. 9.2.4 DAC full-scale error
      5. 9.2.5 DAC differential non-linearity (DNL)
      6. 9.2.6 DAC integral non-linearity (INL)
      7. 9.2.7 DAC total unadjusted error (TUE)
    3. 9.3 DAC output considerations
      1. 9.3.1 DAC linear range
      2. 9.3.2 DAC settling time
      3. 9.3.3 DAC load regulation
    4. 9.4 Notes
  10. 10Mathematical models
    1. 10.1 Laplace transforms
    2. 10.2 Transfer function
    3. 10.3 Transient response
    4. 10.4 Frequency response
    5. 10.5 Z-domain
    6. 10.6 Notes
  11. 11Important Notice

7.2 Types of encoders

Position Encoders are used to obtain position, direction and speed information from machines in order to determine the mechanical position of an object. This mechanical position is an "absolute position". They may also be used to determine a change in position between the encoder and object as well. The change in position in relation to the object and encoder would be an incremental change. Position Encoders are widely used in the industrial arena for sensing the position of tooling and multi-axis positioning. There are many different types of encoders, but they basically fall into four main sensing techniques. Those being:

  • Mechanical
  • Magnetic
  • Optical
  • Electromagnetic

Within those categories, there are two differing encoder measurement types:
  • Absolute
  • Incremental (some incremental encoders are classified as quadrature encoders)

An encoder with an optical sensing type interprets data in pulses of light which can then be used to determine such things as position, direction and velocity. The shaft rotates a disc with opaque segments that represent a particular pattern. These encoders can determine the movement of an object for "rotary" or "shaft" applications while determining exact position in "linear" functions. This encoder sensing technique can be used in various applications such as printers, CNC milling machines and robotics.