User guide

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VTB USER GUIDE
6.6 VCB Variables (CanOpen or EtherCAT)
The variables of type VCB are common variables which reflect the state of variables allocated in remote device connected
at the central unit by field-bus like CANOPEN or ETHERCAT. These variables aren't defined directly by VTB environment
but come from an external configurator which defines the field-bus typology and the connected devices. Practically the
declaration is made automatically by the configurator and compiler application making them available to OBJECT or to
WRITTEN SOURCE CODE. Refer to the chapters CANOPEN CONFIGURATOR and ETHERCAT CONFIGURATOR.
In other words variables VCB are the shared resources of an external device connected by field-bus. For example a
brushless motor driver will make available a lot of variables referred to MOTION, while an I/O device will make available
variables referred to management of INPUT and OUTPUT channels.
Unlike other types of variables, the VCB ones are ever GLOBAL and then visible from all the page and all the tasks.
Variables VCB declared by configurator can be used in the SOURCE CODE as well in the property of the OBJECTS that
make use.
There isn't a list of these variables, to use them we have to refer simply writing its name.
USE OF A VARIABLE VCB IN THE SOURCE CODE
To use a variable VCD we have to refer simply writing its name.
If encoderx >=10000 ‘ encoderx is a variable VCB
……………
endif