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Figure 37: Home to Sensor then Marker Profile (Calculated Offset)
+Velocity
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Home Initiate
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Figure 39: Home to Sensor (Back Off Before Homing)
5.3.4.2 Go Forward To Next Sensor
On some machines, motion in a certain direction may be prohibited due to mechanical design. In this case, the Back
Velocity
Home Accel
Home Initiate
Encoder Marker
External Sensor
Home Velocity
Home Offset
Home Decel
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External Sensor Activates wait for next Encoder Marker
Off Before Homing option may not be practical. In this case, if the Home Sensor is active when the Home is initiated, the motor continues in the programmed direction until the next "Rising Edge" of the external home sensor is detected. Figure 40 shows the Home to Sensor profile when the Home Sensor is active when home is initiated and Go Forward To Next Sensor is selected.
Velocity
Home Velocity
Home Accel | Home Decel |
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Figure 38: Home to Sensor then Marker Profile Specified Offset)
5.3.4 If On Sensor Options
In a Home to Sensor, or Home to Sensor then Marker profile special conditions must be created to handle the situation when the External Sensor is already active when Home is initiated. Different users want the system to act differently in this condition, so the
5.3.4.1 Back Off Before Homing
If the Home Sensor is active when home is initiated, one option is to move the motor in the direction opposite from the programmed direction until the home sensor deactivates, and then again in the positive direction until the home sensor activates. Figure 39 shows the Home to Sensor profile when the Home Sensor is active when the home is initiated and Back Off Before Homing is selected.
Home Initiate
External Home Sensor
First rising edge is used as Home reference
Figure 40: Home to Sensor (Go Forward To Next Sensor)
5.4 Index
An Index profile is used to move the motor a precise distance or to a specific position. There are many different applications that can be solved using different combinations of Index types. The five major types of Indexes are Absolute, Incremental, Registration, Rotary Plus, and Rotary Minus. Each of these Index types are described in detail below.
5.4.1 Absolute Index
An Absolute Index is used to move the motor to a specific
How Motion Works | www.emersonct.com | 25 |
