How to use this on a job
The encoder label and the counter setting must describe the same events. One pulse cycle on channel A can become one, two or four counts depending on decoding. Establish that before scaling position.
- 01
Enter cycles per revolution on one encoder channel, then choose the counter’s x1, x2 or x4 decoding. Do not multiply a manufacturer’s already-decoded counts-per-revolution value again.
- 02
Enter mechanical travel for one encoder revolution. For a directly coupled measuring wheel use its working circumference; for a screw use its lead; for a geared encoder include the ratio first.
- 03
Enter speed and target travel. Compare channel pulse frequency with the input hardware’s rating, and decoded count frequency with the counter’s supported mode. Fractional target counts require a deliberate rounding decision in the application.
Work through one example
distance [mm] = counts × travel/rev ÷ counts/rev
A 1,000-cycle encoder with x4 decoding produces 4,000 counts per revolution. At 200 mm travel per revolution, each count represents 0.05 mm. Moving 50 mm requires 1,000 counts. At 60 rpm, the A-channel frequency is 1 kHz while the decoded count rate is 4 kHz.
Before you trust the answer
PPR and CPR are not used consistently across manufacturers. This calculator’s PPR means complete cycles on one channel. Resolution is not accuracy: wheel slip, eccentricity, backlash and missed edges can dominate the error even when the arithmetic is exact.