TMC 188/40 Motion Control Module
Appendix C: QSBX/40 Module
Delta Computer Systems, Inc. 360/254-8688
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Maximum Speed And Quadrature Encoder Counts
The maximum quadrature encoder speed for the QSBX/40 is 200 kHz. The QSBX/40 counts each
edge of the quadrature input, so a 1000 pulse per revolution (PPR) quadrature encoder would
generate 4000 counts per revolution. For example:
200 kHz = 800,000 quadrature encoder counts per second
MAX RPM = (800,000 counts per second / 4 counts per encoder pulse) / PPR x 60 seconds
MAX RPM = 12,000,000 / PPR
A system with a 250 PPR quadrature encoder would have a maximum speed of 48,000 RPM.
Overdrive Error
An overdrive error during a move could indicate the quadrature encoder signal has been lost. We
recommend clearing the overdrive bit (bit 4, 0EFFF) in both the HALT and ESTOP masks so the
drive output is disabled immediately when an overdrive error occurs.
