Equipments (Devices) > PLC200 > Program > Hardware

Block that continuously reads the pulse value of an encoder according to a type of reading chosen.

Ladder Representation

Block Structure

Variable Type	Name	Data Type	Description
VAR_INPUT	EN	BOOL	Block enabling
VAR_INPUT	Source#	BYTE	Counting source
VAR_OUTPUT	ENO	BOOL	Output enabling
VAR_OUTPUT	Value	DINT DWORD UDINT	Counting value
VAR	READENC_INST_0	READENC	Instance of access to block structure

Operation

When this block has a TRUE value in EN, it gets the number of pulses counted in the encoder, as selected in Source #, and transfers them to Value. At each leading edge, Value is reset to zero.

When EN has FALSE value, Value remains unchanged.

The ENO value forwards to the next Ladder block the EN value after the operation is completed.

Block Flowchart

READENC_flowchart

Example in Ladder

READENC_example01

The above example, when identifying a leading edge on DI1, starts counting the number of pulses in the encoder connected in quadrature conformation AB, storing the value in VALUE. The block ends with success, ENO output is activated.

Example in ST

The example below displays the instructions for applying the example above in the ST language.

VAR

VALUE : UDINT;

READENC_INST_0 : FB_READENC;

END_VAR

READENC_INST_0.EN := DI1;

READENC_INST_0(Source:=0);

VALUE := READENC_INST_0.Value;

DO1 := READENC_INST_0.ENO;