Emerson FM-3 - Manual (Page 25)

11
Operational Overview
Sensor and Marker
Selecting Sensor and Marker means the reference position is established using the first
marker rising edge after the device sees the rising edge of the Home Sensor input function.
Figure 9: Sensor and Marker Home Reference Position Example 1
Accuracy and Repeatability
The amount of accuracy your application requires will determine the Home Reference option
you select. Homing to an external sensor only will establish a repeatable home position within
0.04 revolutions at 3000 RPMs (800
µsec sensor capture interval).
Note
The data above assumes the use of a perfectly repeatable home sensor.
In Sensor and Marker applications, the marker must be at least 800
µsec after the rising edge
of the sensor input to be considered a valid marker pulse.
Note
At 1000 RPM, the motor will travel 0.0133 revolutions (or 4.8°) in 800
µsec.