Figure 5-29. Relationship Between Scaled And Unscaled Formats For Offset Bipolar, Bipolar, Unipolar, And Negative Unipolar Scaling Selection In The Tpu2000 And 2000R - ABB TPU2000 Technical Manual

Within following discussions of scaling parameters, it should be remembered that the bit scale shall be referred to
as the quantity "N" which is used extensively for the final scaled value calculation. N shall be a value of 16,12,8,4,
or 2, which corresponds to the Bit Scale type referred to in Table 5-10 above.
Figure 5-29. Relationship Between Scaled and Unscaled Formats for Offset Bipolar, Bipolar,
Unipolar, and Negative Unipolar Scaling Selection in the TPU2000 and 2000R
If one were to mathematically compute the minimum and maximum values as described above in Table 5-10 and
relate the values to the unscaled full scale + and full scale – values, the following equations would result from the
analysis.
Data Type Definitions
EQUATION 1:
Offset Bipolar
EQUATION 2:
Bipolar
TPU2000/2000R Modbus/Modbus Plus Automation Guide
Unscaled Scaled
Value In The Value Reported To
DPU2000R the Host Via Network
+ Full Scale Table 2 Maximum Value
Table 2 Minimum Value
0
UNIPOLAR
SCALING
Unscaled Scaled
Value In The Value ReportedTo the
DPU2000R Host Via Network
+ Full Scale Table 2 Maximum Value
0 Table 2 Maximum Value/2
- Full Scale
Table 2 Minimum Value
OFFSET
BIPOLAR
SCALING
Value Ranges
N
(0 to +2
N-1
(-2 to + 2
Unscaled
Value In The
DPU2000R
0
Table 2 Minimum Value
- Full Scale Table 2 Maximum Value
NEGATIVE
UNIPOLAR
SCALING
Unscaled
Value In The
DPU2000R
+ Full Scale
0
- Full Scale
BIPOLAR
SCALING
N-1
-1) where 0 = -FS, 2 -1 = 0 and 2
N-1 N-1
-1) where -2 = -FS, 0 = 0 and 2
Scaled
Value Reported To
the Host Via Network
Scaled
Value ReportedTo the
Host Via Network
Table 2 Maximum Value
0
Table 2 Minimum Value
N
-1 = +FS
N-1
-1 = +FS
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