Beckhoff BC**50 Series, Документация

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Programming
BC5250 59 Version: 2.0.0
Fig. 54: Changing variable links
Fig. 55: Linking a variable with an input
In the default configuration all Bus Terminals are assigned fixed addresses. If a Bus Terminal is inserted, the
whole address range may be shifted. The TwinCAT configuration enables allocated variables to be linked to
a Bus Terminal, as required. This is parameterized in the System Manager, and the configuration is then
downloaded to the Bus Terminal Controller (see
TwinCAT configuration [
}
27] ). It is also possible to upload
an existing TwinCAT configuration.
5.10 Communication between TwinCAT and BX/BCxx50
For transferring data from TwinCAT to the Bus Terminal Controller, it makes sense to organize the data in a
structure. Please note the following to account for the differences in data management on the two systems.
• If two different data types are sent in sequence (e.g. byte and INT), the following variable is set to the
next even address offset
• Boolean variables should never be allocated individually within a structure, since they would invariably
occupy 1 byte. Boolean expressions should always be masked in a byte or word.