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Timer Encoder Mode Transition Error Interrupt Based Query.

Associate II

Hi people,

The encoder failures can be detected by the timing unit. Transition errors can be found in encoder systems. A state diagram can be used to depict the reading on the two inputs, which equates to a 2-bit gray code. It is predicted that only one bit will change at once. An incorrect transition may result in a transition error interruption.

I need to know which callback will be called, when the transition error occurs with corrupted encoder values flow through the channels(Means consider B Channel wire cut off Scenario). And also what kind of configurations needed to pick up the transition error interrupt.

Thanks in advance for the solution.

Reference :


Santhosh Kumar V


ST Employee

Hello @SKuma.24 

For encoder configurations where 2 quadrature signals are available, it is possible to detect
transition errors. An erroneous transition sets transition error interrupt flag in the TIM status register. A transition error interrupt is generated if the transition error interrupt is set in TIMx DMA/Interrupt enable register, Well when the transition error is detected in encoder mode the TIM DMA error callback is called.
In the case of encoder with an index signal, it is possible to detect abnormal operation resulting in an excessive number of pulses per revolution.