SBAA530 September   2021 TMAG5170 , TMAG5170-Q1 , TMAG5173-Q1

 

  1.   Trademarks
  2. 1Achieving High Accuracy at High Speeds
  3. 2Optimizing Power Consumption
  4. 3Achieving Greater Flexibility
  5. 4Gaining Higher Reliability
  6. 5Conclusion
  7. 6Additional Resources

4 Gaining Higher Reliability

Factory automation has always needed highly-reliable products. With the advent of Industry 4.0, a reliable diagnostic scheme is vital to achieve zero downtime, or at least minimize downtime as much as possible. In the majority of robotic systems, a multiaxis sensor or rotary encoder determines the angle of each joint in a robotic arm (as shown in Figure 4-1), or each wheel in an autonomous mobile robot, ensuring precise movement and navigation throughout the assembly line and factory floor. Unlike optical encoding solutions that are susceptible to dirt or moisture, the performance of magnetic encoders is unaffected in harsh environments.


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Figure 4-1 Example of a Robotic Arm Using the TMAG5170

A sensor that includes built-in safety measures and enables users to diagnose potential problems that may arise during operation is a requirement for factory automation systems. Table 4-1 summarizes the device- and system-level diagnostics features provided by the TMAG5170.

Table 4-1 TMAG5170 Continuous and User-Enabled Diagnostics
Device-Level diagnostics
Diagnostics Function Benefit
Reliable communication check Cyclic redundancy check (CRC) communication:
  • Checks CRC on received communication
  • Embeds expected CRC frame information for the MCU to check
 Provides a communication solution that does not need interface filtering to reduce noise injection and data corruption
Internal memory and register checks
  • CRCs at power up, upon conversion initiation, and upon sensor configuration
  • The MCU can read configuration register values periodically to confirm accuracy
 Checks sensor signal path to ensure a known good measurement
Signal-path diagnostics Checks for signal path integrity
Per-axis Hall-sensor diagnostics
  • Checks for sensor accuracy and integrity
  • Verifies offset and sensitivity for accuracy
System-Level diagnostics
Diagnostics Function Benefit
Pin continuity Checks for shorts between various pins such as VCC, GND, and Serial Peripheral Interface (SPI) bus pins Adds system-level, long-term reliability by detecting potential hazards that could cause catastrophic failures
Magnetic field out of range Sets threshold value during configuration and compares to the magnetic field Enables redundant field amplitude checks with no additional Hall switches
Ambient temperature out of range On-chip temperature sensor monitors die temperature and compares to a user-defined threshold Alerts the system of a thermal failure event without the additional cost of an external temperature sensor
Power-supply undervoltage, overvoltage and internal low dropout undervoltage Alerts the MCU of out-of-range power-supply voltages Eliminates the need for an external power-management supervisory device

SPI provides reliable communication with the TMAG5170, which includes an alert input/output pin for added functionality, as summarized in Figure 4-2.


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Figure 4-2 TMAG5170 Digital Interface