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VTB USER GUIDE

NG_ENC - ENCODER INPUTS

This function allows to read the quadrature encoder input of each channel equipped on the expansion card NG-IO. The

resolution is 32 bits. This function read only the increment which will be added to a variable passed by its pointer.

Therefore the real encoder counter will be contained in a variable defined in the application and it will can be zeroed in

any time. For a correct processing of the encoders we recommend to use this function only in TASK PLC and then use it

at the occurrence.

The selection of the channel is made by an index from 0 to 15, each expansion manages two channels:

Channel Index

Expansion number

Card 0 (nearest NG35)

Card 1

...

Card 7

Syntax

NG_ENC(Char Chan, Long *Val)

Parameters

Chan Number of channel (from 0 to 15)

val Pointer to a long variable where will be contained the counter

Example

Used variables:

posx LONG ' Counter encoder channel 0

posy LONG ' Counter encoder channel 1

In TASK PLC:

ng_enc(0,posx())

ng_enc(1,posy())

EVERYWHERE:

if posx>25000 ' Read encoder channel 0

. . .

posx=0 ' Reset counter channel 0

endif

if posy>200000 ' Read encoder channel 1

. . .

posy=1000 ' Preset counter channel 1

endif

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Vision VTB-101 Guide de l'utilisateur Page 77