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Bus Fault Finder

Run the Bus Fault Finder MicroSim Fullscreen

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Description

Read eight symptom reports from a servo bus, each with a scan result and the bytes received, and choose the most likely of six causes: wrong port, no motor power, baud rate mismatch, duplicate ID, broken chain link, or noise and a missing ground. Used in Chapter 4.

The six causes come from the table of communication errors in Chapter 4. The reports are illustrative and were written for this MicroSim. The bytes in report 3 are invented and are labeled "illustrative".

Lesson Plan

Grade level: Middle school and up (age 12+). Time: 10 to 15 minutes.

  1. Learn the signs. In Explore mode, press each cause button. Read what its evidence looks like and what to try first.
  2. Eight reports. Read the report, the scan result and the bytes received. Choose the most likely cause and press Check. You get one try for each report, and 6 of 8 is mastery.
  3. Read the feedback. After each answer the sim names the evidence that decides the cause.
  4. Think about it. Reports 2, 7 and 8 all show a silent bus. Which words in each report tell the three apart?

A silent bus is usually the port, the power or the baud rate, and only rarely a broken motor. Let the bytes decide before you change anything.

Specification

The learning objective, evidence of mastery and content for this MicroSim are specified in Chapter 4: Serial and CAN Communication.