Topological Addressing—800 Series I/O Modules with Control Expert
(Original Document)
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Accessing I/O Data Values
Use topological addressing to access I/O data items. Identify the topological location of the module within an 800 series I/O module with Control Expert using the following notation:
%<Exchangetype><Objecttype>[\b.e\]r.m.c[.rank]
where:
NOTE: When addressing,
  1. The [\b.e\] defaults to \1.1\ in a local rack and does not need to be specified.
  2. The rank is an index used to identify different properties of an object with the same data type (value, warning level, error level).
  3. The rank numbering is zero-based, and if the rank is zero, omit the entry.
For detailed information on I/O variables, please refer to the EcoStruxure™ Control Expert, Program Languages and Structure, Reference Manual.
Reading Values: An Example
To read
Action
input value (rank = 0) from channel 7 of an analog module located in slot 6 of a local rack:
Enter
%IW1.6.7[.0]
input value (rank = 0) from channel 7 of an analog module located in slot 6 of drop 3 of RIO bus 2:
Enter
%IW\2.3\1.6.7[.0]
’out of range’ value (rank = 1) from channel 7 of an analog module located in slot 6 of a local rack:
Enter
%I1.6.7.1[.0]