SPRACN0F October   2021  – March 2023 F29H850TU , F29H859TU-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 , TMS320F28374D , TMS320F28374S , TMS320F28375D , TMS320F28375S , TMS320F28375S-Q1 , TMS320F28376D , TMS320F28376S , TMS320F28377S , TMS320F28377S-Q1 , TMS320F28378D , TMS320F28378S , TMS320F28379D , TMS320F28379D-Q1 , TMS320F28379S , TMS320F28384D , TMS320F28384S , TMS320F28386D , TMS320F28386S , TMS320F28388D , TMS320F28388S , TMS320F28P650DH , TMS320F28P650DK , TMS320F28P650SH , TMS320F28P650SK , TMS320F28P659DH-Q1 , TMS320F28P659DK-Q1 , TMS320F28P659SH-Q1

 

  1.    The Essential Guide for Developing With C2000™ Real-Time Microcontrollers
  2.   Trademarks
  3. 1C2000 and Real-Time Control
    1. 1.1 Getting Started Resources
    2. 1.2 Processing
    3. 1.3 Control
    4. 1.4 Sensing
    5. 1.5 Interface
    6. 1.6 Functional Safety
  4. 2Sensing Key Technologies
    1. 2.1 Accurate Digital Domain Representation of Analog Signals
      1. 2.1.1 Value Proposition
      2. 2.1.2 In Depth
      3. 2.1.3 Device List
      4. 2.1.4 Hardware Platforms and Software Examples
      5. 2.1.5 Documentation
    2. 2.2 Optimizing Acquisition Time vs Circuit Complexity for Analog Inputs
      1. 2.2.1 Value Proposition
      2. 2.2.2 In Depth
      3. 2.2.3 Device List
      4. 2.2.4 Hardware Platforms and Software Examples
      5. 2.2.5 Documentation
    3. 2.3 Hardware Based Monitoring of Dual-Thresholds Using a Single Pin Reference
      1. 2.3.1 Value Proposition
      2. 2.3.2 In Depth
      3. 2.3.3 Device List
      4. 2.3.4 Hardware Platforms and Software Examples
      5. 2.3.5 Documentation
    4. 2.4 Resolving Tolerance and Aging Effects During ADC Sampling
      1. 2.4.1 Value Proposition
      2. 2.4.2 In Depth
      3. 2.4.3 Device List
      4. 2.4.4 Hardware Platforms and Software Examples
      5. 2.4.5 Documentation
    5. 2.5 Realizing Rotary Sensing Solutions Using C2000 Configurable Logic Block
      1. 2.5.1 Value Proposition
      2. 2.5.2 In Depth
      3. 2.5.3 Device List
      4. 2.5.4 Hardware Platforms and Software Examples
      5. 2.5.5 Documentation
    6. 2.6 Smart Sensing Across An Isolation Boundary
      1. 2.6.1 Value Proposition
      2. 2.6.2 In Depth
      3. 2.6.3 Device List
      4. 2.6.4 Hardware Platforms and Software Examples
      5. 2.6.5 Documentation
    7. 2.7 Enabling Intra-Period Updates in High Bandwidth Control Topologies
      1. 2.7.1 Value Proposition
      2. 2.7.2 In Depth
      3. 2.7.3 Device List
      4. 2.7.4 Hardware Platforms and Software Examples
      5. 2.7.5 Documentation
    8. 2.8 Accurate Monitoring of Real-Time Control System Events Without the Need for Signal Conditioning
      1. 2.8.1 Value Proposition
      2. 2.8.2 In Depth
      3. 2.8.3 Device List
      4. 2.8.4 Hardware Platforms and Software Examples
      5. 2.8.5 Documentation
  5. 3Processing Key Technologies
    1. 3.1 Accelerated Trigonometric Math Functions
      1. 3.1.1 Value Proposition
      2. 3.1.2 In Depth
      3. 3.1.3 Device List
      4. 3.1.4 Hardware Platforms and Software Examples
      5. 3.1.5 Documentation
    2. 3.2 Fast Onboard Integer Division
      1. 3.2.1 Value Proposition
      2. 3.2.2 In Depth
      3. 3.2.3 Device List
      4. 3.2.4 Hardware Platforms and Software Platforms
      5. 3.2.5 Documentation
    3. 3.3 Hardware Support for Double-Precision Floating-Point Operations
      1. 3.3.1 Value Proposition
      2. 3.3.2 In Depth
      3. 3.3.3 Device List
      4. 3.3.4 Hardware Platforms and Software Examples
      5. 3.3.5 Documentation
    4. 3.4 Increasing Control Loop Bandwidth With An Independent Processing Unit
      1. 3.4.1 Value Proposition
      2. 3.4.2 In Depth
      3. 3.4.3 Device List
      4. 3.4.4 Hardware Platforms and Software Examples
      5. 3.4.5 Documentation
    5. 3.5 Flexible System Interconnect: C2000 X-Bar
      1. 3.5.1 Value Proposition
      2. 3.5.2 In Depth
      3. 3.5.3 Device List
      4. 3.5.4 Hardware Platforms and Software Examples
      5. 3.5.5 Documentation
    6. 3.6 Improving Control Performance With Nonlinear PID Control
      1. 3.6.1 Value Proposition
      2. 3.6.2 In Depth
      3. 3.6.3 Device List
      4. 3.6.4 Hardware Platforms and Software Examples
      5. 3.6.5 Documentation
    7. 3.7 Understanding Flash Memory Performance In Real-Time Control Applications
      1. 3.7.1 Value Proposition
      2. 3.7.2 In Depth
      3. 3.7.3 Device List
      4. 3.7.4 Hardware Platforms and Software Examples
      5. 3.7.5 Documentation
    8. 3.8 Deterministic Program Execution With the C28x DSP Core
      1. 3.8.1 Value Proposition
      2. 3.8.2 In Depth
      3. 3.8.3 Device List
      4. 3.8.4 Hardware Platforms and Software Examples
      5. 3.8.5 Documentation
    9. 3.9 Efficient Live Firmware Updates (LFU) and Firmware Over-The-Air (FOTA) updates
      1. 3.9.1 Value Proposition
      2. 3.9.2 In Depth
      3. 3.9.3 Device List
      4. 3.9.4 Hardware Platforms and Software Examples
      5. 3.9.5 Documentation
  6. 4Control Key Technologies
    1. 4.1 Reducing Limit Cycling in Control Systems With C2000 HRPWMs
      1. 4.1.1 Value Proposition
      2. 4.1.2 In Depth
      3. 4.1.3 Device List
      4. 4.1.4 Hardware Platforms and Software Examples
      5. 4.1.5 Documentation
    2. 4.2 Shoot Through Prevention for Current Control Topologies With Configurable Deadband
      1. 4.2.1 Value Proposition
      2. 4.2.2 In Depth
      3. 4.2.3 Device List
      4. 4.2.4 Documentation
    3. 4.3 On-Chip Hardware Customization Using the C2000 Configurable Logic Block
      1. 4.3.1 Value Proposition
      2. 4.3.2 In Depth
      3. 4.3.3 Device List
      4. 4.3.4 Hardware Platforms and Software Examples
      5. 4.3.5 Documentation
    4. 4.4 Fast Detection of Over and Under Currents and Voltages
      1. 4.4.1 Value Proposition
      2. 4.4.2 In Depth
      3. 4.4.3 Device List
      4. 4.4.4 Hardware Platforms and Software Examples
      5. 4.4.5 Documentation
    5. 4.5 Improving System Power Density With High Resolution Phase Control
      1. 4.5.1 Value Proposition
      2. 4.5.2 In Depth
      3. 4.5.3 Device List
      4. 4.5.4 Hardware Platforms and Software Examples
      5. 4.5.5 Documentation
    6. 4.6 Safe and Optimized PWM Updates in High-Frequency, Multi-Phase and Variable Frequency Topologies
      1. 4.6.1 Value Proposition
      2. 4.6.2 In Depth
      3. 4.6.3 Device List
      4. 4.6.4 Hardware Platforms and Software Examples
      5. 4.6.5 Documentation
    7. 4.7 Solving Event Synchronization Across Multiple Controllers in Decentralized Control Systems
      1. 4.7.1 Value Proposition
      2. 4.7.2 In Depth
      3. 4.7.3 Device List
      4. 4.7.4 Hardware Platforms and Software Examples
      5. 4.7.5 Documentation
  7. 5Interface Key Technologies
    1. 5.1 Direct Host Control of C2000 Peripherals
      1. 5.1.1 Value Proposition
      2. 5.1.2 In Depth
        1. 5.1.2.1 HIC Bridge for FSI Applications
        2. 5.1.2.2 HIC Bridge for Position Encoder Applications Using CLB
      3. 5.1.3 Device List
      4. 5.1.4 Hardware Platforms and Software Examples
      5. 5.1.5 Documentation
    2. 5.2 Securing External Communications and Firmware Updates With an AES Engine
      1. 5.2.1 Value Proposition
      2. 5.2.2 In Depth
      3. 5.2.3 Device List
      4. 5.2.4 Hardware Platforms and Software Examples
      5. 5.2.5 Documentation
    3. 5.3 Distributed Real-Time Control Across an Isolation Boundary
      1. 5.3.1 Value Proposition
      2. 5.3.2 In Depth
      3. 5.3.3 Device List
      4. 5.3.4 Hardware Platforms and Software Examples
      5. 5.3.5 Documentation
    4. 5.4 Custom Tests and Data Pattern Generation Using the Embedded Pattern Generator (EPG)
      1. 5.4.1 Value Proposition
      2. 5.4.2 In Depth
      3. 5.4.3 Device List
      4. 5.4.4 Hardware Platforms and Software Examples
      5. 5.4.5 Documentation
  8. 6Safety Key Technologies
    1. 6.1 Non-Intrusive Run Time Monitoring and Diagnostics as Part of the Control Loop
      1. 6.1.1 Value Proposition
      2. 6.1.2 In Depth
      3. 6.1.3 Device List
      4. 6.1.4 Hardware Platforms and Software Examples
      5. 6.1.5 Documentation
    2. 6.2 Hardware Built-In Self-Test of the C28x CPU
      1. 6.2.1 Value Proposition
      2. 6.2.2 In Depth
      3. 6.2.3 Device List
      4. 6.2.4 Hardware Platforms and Software Examples
      5. 6.2.5 Documentation
    3. 6.3 Zero CPU Overhead Cyclic Redundancy Check for Embedded On-Chip Memories
      1. 6.3.1 Value Proposition
      2. 6.3.2 In Depth
      3. 6.3.3 Device List
      4. 6.3.4 Hardware Platforms and Software Examples
      5. 6.3.5 Documentation
    4. 6.4 Boot Code Authentication Prior To Code Execution
      1. 6.4.1 Value Proposition
      2. 6.4.2 In Depth
      3. 6.4.3 Device List
      4. 6.4.4 Hardware Platforms and Software Examples
        1. 6.4.4.1 Documentation
  9. 7References
    1. 7.1 Device List
    2. 7.2 Hardware/Software Resources
    3. 7.3 Documentation
  10. 8Revision History

2.5.2 In Depth

A digital rotary encoder is a device that converts the position of a shaft to a digital signal. There are two main types of encoders:

  • Absolute Encoders (#T5843526-237): The output of an absolute encoder indicates the current angular position in a message sent back to the master as defined by a particular protocol.
  • Incremental Encoders: The output of an incremental encoder provides information in a train of modulated pulses that are typically further processed by the system master into information such as speed, distance and position.

GUID-9D40A2D1-E64A-498C-B1CB-30FEF76E0D1C-low.gif Figure 2-5 Industrial Servo Drive With T-Format Absolute Position Encoder Interface

C2000 CLB technology enables an integrated solution to interface to the most popular digital rotary position encoders, eliminating the necessity for external field-programmable gate arrays (FPGAs) or application-specific integrated circuits (ASICs). The PositionManager BoosterPackplug-in module is a flexible low voltage platform intended for evaluating various encoder interfaces and designed to work with multiple C2000 LaunchPad development kits such as the LAUNCHXL-F28379D, LAUNCHXL-F280049C, or the LAUNCHXL-F280025C.

Below are examples of encoders that are available for evaluation today as part of the Motor Control SDK software package. Future updates are planned to add examples for both the BiSS-C and EnDAT22 protocols.

  • T-Format Absolute Encoder Interface:

    The Tamagawa T-Format protocol is a popular digital, bidirectional interface for absolute encoders. The easy-to-use library and example software delivered with TIDM-1011 demonstrates Tamagawa's T-Format standard. In this example, the T-Format absolute encoder interface is integrated into the C2000 using on-chip resources such as the CLB, SPI, and GPIO as shown in #T5843526-237. This TI Design includes the following features:

    • A T-Format encoder interface library and CRC library that implements protocol commands
    • A demonstration project (with full source code access) to exercise the T-Format commands
    • Fully supported by the C2000 CLB Tool integrated inside Code Composer Studio

  • T-Format Evaluation in High-Bandwidth Current Loop Applications:

    With the recent C2000 MCUs such as TMS320F2837x and TMS320F28004x, it is possible to implement Fast Current Loop (FCL) algorithms that provide a high current loop bandwidth with the same external hardware as used in classical Field Oriented Control (FOC) methods. TI has developed the FCL algorithm on these MCUs and implemented it on the DesignDRIVE IDDK platform. The T-Format encoder interface has been integrated into an evaluation implementation of FCL algorithms on C2000 devices.

    Quick Response Control of PMSM Using Fast Current Loop studies the frequency response analysis of current loops in real time and also verifies the interface logic for the T-format encoder interface implemented in TIDM-1011. The position loop in this example can be closed using a QEP encoder or a T-format encoder and FCL can be implemented in both cases.

  • Pulse Train Output (PTO) QepDiv and PulseGen:

    Incremental rotary encoders output a pulse train to indicate that the shaft being monitored has moved. The system master typically processes this pulse train to determine information such as speed, distance and position. In the QepDiv implementation, position information is sent from the encoder to the Enhanced Quadrature Encoder Pulse (eQEP) module on a C2000 MCU. In the PulseGen case a custom pulse stream is generated to meet the system needs. The PTO-QepDiv example demonstrates how the CLB can be used to generate a divided pulse stream from these eQEP inputs as shown in #T5843526-239. The divided pulse stream can then be sent to another device in the system. Both the QepDiv and PulseGen examples are documented in the C2000 Position Manager PTO API Reference Guide.

    GUID-27E4B4FB-3FF7-441C-9EBC-A209087334A5-low.gif Figure 2-6 QepDIv Input and Output Diagram