Component: Quadrature Encoder (General Input)

Author	Matrix TSL
Version	1.5
Category	General Input

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 for the component source code: 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

Downloadable macro reference

	CheckForChanges
Polling function to check changes Returns 1 for chaged, 0 for no change, 255 for error
- BYTE	Return

	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

	WriteCounter32
Sets the value of the internal count variable. Range: -2147483648 to 2147483647
- LONG	Value
Range: -2147483648 to 2147483647
- VOID	Return

	Enable
Enables the use of the quad encoder If this is not called, the read functions will return zeros
- VOID	Return

	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

	ReadCounter
Reads the current dial counter This is a counter from -32768 to 32767
- INT	Return

	WriteCounter
Sets the value of the internal count variable. Range: -32768 to 32767
- INT	Value
Range: -32768 to 32767
- VOID	Return

	ResetCounter
Resets the current dial counter to zero
- VOID	Return

	ReadCounter32
Reads the current dial counter as a 32-bit value This is a counter from -2147483648 to 2147483647
- LONG	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.
	Encoder Resolution
	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
	Connections
	A
Input pin A
	B
Input Pin B
	Simulation
	Repeat Rate
Simulated repeat rate when clicking and rotating the encoder
	Rotation Increment
Number of degrees to rotate when performing a single quadrature pin transition.
	Scope Traces