Objects associated with specific applications
2.2
Implicit exchanges
Implicit exchanges
Presentation A built-in specific application interface where the addition of a module automatically enhances the application of language objects making it possible to program this interface or module.
These objects correspond to the images of the I/Os of the module or built-in specific application module.
The %I bits and the %IW words, images of the module's input values are updated automatically in the PLC processor at the start of the task, whether the task is in
RUN or STOP mode.
The %Q bits and %QW words, images of the module's output values are updated automatically in the module by the processor at the end of the task, with the task in
RUN mode.
Note: When the task in STOP mode, depending on the configuration chosen: z the outputs are in the fallback position (fallback mode), z the outputs are maintained at their last value (maintain mode).
Illustration The graph illustrates the operational cycle relating to a PLC task (cyclical execution).
Internal processing
Acquisition of input
RUN STOP
Program processing
Updating of output
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Objects associated with specific applications
Examples
Object
%I103.1
%IW4.2
%IW203.2:X4
%Q306.5
%I6.5.ERR
%I107.MOD.ERR -
The table below shows several examples of implicit exchanges relating to a given application.
Description Specific application
Discrete
Analog
-
Counting
Discrete
Gives the status of channel 1 of the module located in position 3 of rack 1.
Gives the analog value of channel 2 of the module located in position 4 of rack 0.
Gives the status of the capture input of the module located in position 3 of rack 2.
Gives the status of channel 5 of the module located in position 6 of rack 3.
Indicates, when the bit is set to 1, that channel 5 of the module located in position
6 of rack 0 is faulty.
Indicates, when the bit is set to 1, that the module located in position 7 of rack 1 is faulty.
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