Atlas Copco PowerMACS 4000, User Manual

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Peripheral Devices
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8.14.1 Subscriptions
This function requires API version 10.1.0 or later and TC software version 7.2.3 or later.
Process data can be fetched by cyclically calling read functions. It is also possible to set up subscriptions
that will automatically call application functions when new data has arrived. This will make the response
fast without increasing the load.
To handle subscriptions the application should define specific ActiveX event functions. When new data
arrives the API will raise an ActiveX event which calls these functions. Inside these functions the
application can take care of the received data.
The parameters of the ActiveX event functions vary depending on type of subscribed data.
Subscribed Data Parameters
Cycle Data Station, Id
Event EventData object
Trace Station, Bolt, Spindle, ID, Status
Station Status Station, Station status, Mode, Workpiece ID, Number of bolts, Bolt status
The application should call subscribe methods to switch subscriptions on or off.
Note! The event functions are called on the API communication thread. This will not continue execution
until the event function is finished. Therefore, do not do any lengthy handling inside the event function.
Also beware that the GUI is executed on a different thread. Trying to update any GUI control directly from
within the event function can cause unpredictable results.