modules have different associated s.
The IODDTs are predefined by the manufacturer. They contain input/output language objects belonging to a channel of an application-specific module.
NOTE: IODDT variables can be created in two different ways:
There are four types of IODDT for remote Discrete input/output modules:
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T_DIS_IN_GEN,
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T_DIS_IN_FIP_STD,
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T_DIS_OUT_GEN,
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T_DIS_OUT_STD.
Each IODDT contains a group of language objects which are used to control them and check their operation.
There are two types of language objects:
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Implicit exchange objects, which are automatically exchanged on each cycle of the task associated with the module,
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Explicit exchange objects, which are exchanged when requested to do so by the project, using explicit exchange instructions.
Implicit exchanges concern the module inputs/outputs: process value results, information and commands.
Explicit exchanges are used to set up the module's parameters and for module diagnostics.
