Component: Quadrature Encoder (General Input)
| Author | Matrix TSL |
| Version | 1.5 |
| Category | General Input |
Contents
Quadrature Encoder component
Quadrature Encoder component implements a rotary encoder connected to two pins. Quadrature Encoders provides incremental positioning rather than absolute positioning.
Component Source Code
Please click here to download the component source project: FC_Comp_Source_Encoder_Quadrature.fcfx
Please click here to view the component source code (Beta): FC_Comp_Source_Encoder_Quadrature.fcfx
Detailed description
Mechanical encoders can be a bit electrically noisy when switching and so to have reliable operation it is recommended to have a simple filter as shown here.
Examples
Polling
Example program showing how to use a quadrature encoder component using a polling method.
Quad_Encoder_Test
Timer Interrupt Based Polling
Example program showing how to use a quadrature encoder component using a polling method via a timer interrupt.
Quad_Encoder_Timer
Interrupt On Change
Example program showing how to use a quadrature encoder component using a interrupt on pin state change interrupt (IOC).
Quad_Encoder_IOC
Macro reference
CheckForChanges
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CheckForChanges |
| Polling function to check changes Returns 1 for chaged, 0 for no change, 255 for error | |
 - BYTE
|
Return |
Disable
|
|
Disable |
| Disables the use of the quad encoder Once this ist called, the read functions will return zeros until the next Enable() call | |
 - VOID
|
Return |
Enable
|
|
Enable |
| Enables the use of the quad encoder If this is not called, the read functions will return zeros | |
| - VOID
|
Return |
ReadCounter
|
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ReadCounter |
| Reads the current dial counter This is a counter from -32768 to 32767 | |
 - INT
|
Return |
ReadCounter32
|
|
ReadCounter32 |
| Reads the current dial counter as a 32-bit value This is a counter from -2147483648 to 2147483647 | |
 - LONG
|
Return |
ResetCounter
|
|
ResetCounter |
| Resets the current dial counter to zero | |
| - VOID
|
Return |
Rotate
|
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Rotate |
| Simulation Rotate function to allow accurate rotation during simulation. Automatically called by any attached coupling or gearbox component. | |
 - FLOAT
|
Angle |
| Amount to rotate the shaft input in degrees | |
| - VOID
|
Return |
WriteCounter
|
|
WriteCounter |
| Sets the value of the internal count variable. Range: -32768 to 32767 | |
| - INT
|
Value |
| Range: -32768 to 32767 | |
| - VOID
|
Return |
WriteCounter32
|
|
WriteCounter32 |
| Sets the value of the internal count variable. Range: -2147483648 to 2147483647 | |
| - LONG
|
Value |
| Range: -2147483648 to 2147483647 | |
| - VOID
|
Return |
Property reference
|
Properties |
|
Count Variable |
|
Variable Type |
| Selects the size of the encoder count variable depending on the number of encoder counts required to be stored. The 16 bit variable counter is accessed via the ReadCounter and WriteCounter functions. The 32 bit variable counter is accessed via the ReadCounter32 and WriteCounter32 functions. | |
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Encoder Resolution |
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Post Scaler |
| Encoders with a mechanical click will often have 4 transitions per click. 1:1 would provide the maximum output resolution. 1:4 would provide the encoder click count. | |
|
Edges Per Revolution |
| Number of signal transitions per revolution. E.g. for a 360 degree encoder you would likely get 360 x 4 = 1440 transitions and an accuracy of 0.25 degrees. | |
|
Resolution |
| The resolution of the encoder in degrees | |
|
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Connections |
|
A |
| Input pin A | |
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B |
| Input Pin B | |
|
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Simulation |
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Repeat Rate |
| Simulated repeat rate when clicking and rotating the encoder | |
|
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Rotation Increment |
| Number of degrees to rotate when performing a single quadrature pin transition. | |
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Scope Traces |
