Method AbsolutePosition¶
AbsolutePosition method allows users to define machine zero based on the encoder reading and a user-defined offset. The axis does not move. Required configuration for method AbsolutePosition describes the inputs that are required to have a connected signal for this method to operate. Homing switches, direction and velocities do not have to be configured.
Note
The state of the axis does not have to be Operation Enabled to execute this method.
For the AbsolutePosition method, the home offset is calculated as:
HomeOffset = - PositionSensor + UserOffset
As an example, consider the following case: The distance between the encoder zero and the home position is \(10\). In addition, the machine zero shall be at encoder position \(4\).
As distance between the encoder zero and the home position is \(10\), PositionSensor reads \(10\). To get zero value at the desired machine zero position, HomeOffset should be \(-4\). Note that the minus sign is necessary to achieve compensation. Using the equation above, \(-4 = -10\) + UserOffset. Hence UserOffset should be selected as \(6\).
AbsolutePosition method diagram.¶
Position descriptor |
Description |
|---|---|
M |
Machine zero. |
E |
Encoder zero. |
H |
Home position. |
Home pos |
Input name |
Signal |
|---|---|---|
H |
PositionSensor |
Actual signal of position sensor. |
Run exceptions¶
The AbsolutePosition homing method can fail with the run exceptions given in Homing run exceptions for method AbsolutePosition.
Run exception |
Description |
|---|---|
AbortedException |
Resulting home offset is out of bounds. |
OutOfResourcesException |
No commands available during homing procedure. |