GE VersaPoint IC220PBI002 User Manual page 111

Data Area Parameters
Area
Type
Ref
Address
Length
Swap
Bytes
GFK-1911B Chapter 7 Configuration
This value is an index beginning at 1. Read-only.
Specifies whether the data is input or output as well as type, digital or
analog. Value can be Digital In, Analog In, Digital Out, or Analog Out.
Specifies the memory area that is used to map the data area. Regardless of
the reference type used, input areas are considered as consumed and
cannot overlap, while output areas are considered as produced and may
overlap.
Allowable Ranges: %AI, %AQ, %I, %Q, %G, %R, %T, %M.
If the number of bytes is odd, analog memories are not allowed and
selections are limited to: %I, %Q, %G, %M
Specifies the length of the reference. Includes the entire data area by
default. If set to 0, the data area is not mapped.
For discrete memories, the allowable range is [0, 8, 16, ..., X]
For analog memories, the allowable range is [0, 1, 2, ..., X]
The swap bytes field is used to manipulate the byte order. Because Profibus
devices often do not follow the standard, the ability to change byte ordering
is provided. The analog areas travel in MSB and should be swapped if LSB
is required. The effect of swapping bytes is shown on the next page.
▪
If Type is Digital and the module has an odd number of bytes, Swap
Bytes is set to False (no swapping) and read-only.
▪
If Type is Digital and the module has an even number of bytes, default
is set to False. Setting Swap Bytes to True causes the LSB and MSB to
be swapped before the data is mapped into PLC memory.
▪
If Type is Analog, default is set to False. Setting Swap Bytes to True
causes the LSB and MSB to be swapped before the data is mapped
into PLC memory.
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