A CNC shop replaced a Y-axis motor on their vertical machining center. After the change, the axis had a high-frequency vibration at 5000mm/min rapids. No DCS alarm was present. Upon inspection, Parameter 1860 was set to 8,000,000 (from the old motor), but the new motor’s encoder had 16,000,000 pulses. Updating 1860 to 16,000,000 eliminated the vibration immediately.