2.5.2.1 MPG signal input mode
The Commander core can accept two different pulse types, which can be set using the POL[axis](Bit15~16) command.
- Two pulse type (not common) is where pulses are sent to A input to count up and B input to count down. Each pulse input is one count of the encoder.
- A/B phase type (common).
- For an A/B phase type, there should be 90° difference between the pulses from A and B.
- By default, when the A phase leads the B phase motion is in the positive direction, and when B phase leads the A phase motion is in the negative direction. The direction can be changed by POL[axis](Bit14).
- For an A/B phase type you can select x1, x2 or x4 multiplication rate. The figure below shows how the A/B phase counts would be interpolated for a x1, x2, and x4 multiplication rate.
- x1 multiplication – Only the rising edge of the A phase is counted, B phase is not counted and is only used to check the direction of motion.
- x2 multiplication – The rising and falling edge of the A phase is counted, B phase is not counted and is only used to check the direction of motion.
- x4 multiplication – The rising and falling edge of the A and B phase is counted, and used to check the direction of motion.
Maximum frequency input on the MPG line is the maximum pulses that can be input to the MPG input, not the counts. Since most manual pulse generator outputs are rated based on a x4 multiplication rate, the output frequency of pulses is most likely ¼ the count rate output. Please check the datasheet for your manual pulse generator to confirm.
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