Implicit exchanges. Schneider Electric Software PLC Application-Specific Functions, Junior/Pro, 4.5

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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