Floating-Point Support - ProSoft Technology CompactLogix MVI69E-MBS User Manual

MVI69E-MBS ♦ CompactLogix™ Platform
Modbus Serial Enhanced Communication Module
8.3

Floating-Point Support

You can easily move floating point data between the MBS module and other devices as
long as the device supports IEEE 754 Floating Point format. This IEEE format is a 32-bit
single-precision floating-point format.
The logic necessary to move the floating-point data takes advantage of the COP
instruction in Studio 5000. The COP instruction is unique for data movement commands
in that it is an untyped function, meaning that no data conversion is done when data is
moved between controller tags with different data types (that is, it is an image copy, not
a value copy).
The COP instruction to move data from a floating-point controller tag into an integer
controller tag (something you would do to move floating-point values to the module) is
shown below.
This instruction moves one floating-point value in two 16-bit integer images to
MBS.DATA.WriteData[0], which is an integer tag. For multiple floating-point values
increase the Length field by a factor of 2 per floating-point value.
The COP instruction to move data from MBS.DATA.ReadData[0], which is an integer
tag, to a floating-point tag (something you would do to receive floating-point values from
the module) is shown below.
This instruction moves two 16-bit integer registers containing one floating point value
image into the floating-point tag. For multiple values increase the Length field.
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Reference
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