SmartPLC SafeLine AC4S with fieldbus interfaces
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7.3
Access standard input and output data
Content
Options to access input and output data ................................................................................................50
Validity of the interface data ...................................................................................................................51
Process data of the AS-i slaves .............................................................................................................52
Fieldbus data ..........................................................................................................................................54
Process data of the non-safe local devices ............................................................................................56
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► Familiarise yourself with the following CODESYS functions!
Addresses according to IEC standard 61131-3:
→ Online help > CODESYS Development System > Programming Reference >
Operanden > Addresses
Access to IEC address via AT declaration:
→ Online help > CODESYS Development System > Programming Reference >
Declaration > AT Declaration
Definition of an ALIAS for an IEC address:
→ Online help > CODESYS Development System > Programming Reference > Data
Types > References
Coupling of a program variable to an address (mapping):
→ Online help > CODESYS Development System > Configuring I/O Links
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7.3.1
Options to access input and output data
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In a CODESYS project, each input and output has a physical address according to the IEC standard
(e.g. %IW5). CODESYS offers the following options to access this address from a Standard PLC
application and thereby to access the input and outputs data of the device:
Direct access to IEC address
Access to IEC address via AT declaration
Definition of an ALIAS for an IEC address
Link a program variable to an IEC address (mapping)
The IEC addresses (%I, %Q) of the inputs and outputs change if additional safe AS-i slaves
are inserted in the CODESYS project.
► Always use symbolic programming for access to the inputs and outputs.
