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WAGO-I/O-SYSTEM 750 XTR
750-563/040-000 2AO 0/4-20mA/ 6-18V DC/ 16Bit /XTR
4.4.2
Step 2 – Y
The value for Y
input value for the user scaling. With user scaling switched off, the X
transferred unchanged to Y
The calculation is made taking into account the configured data format. The
significance of the result is determined by a gain factor and an offset.
Calculation formula:
Y
= X
1
IN
The user scaling serves to adjust a required process value range to the analog
output range specified by the calibration.
In addition, it is possible to map the calibrated output range of 0 mA ... 20 mA, so
that the analog value of 4 mA is output with a signed process data value of 0 and
currents less than 4 mA can be generated with negative process data values.
The calculation for the user scaling is carried out module-internally in the 32-bit
number range.
When user scaling is used, the required accuracy of the resolution of the analog
correcting range is changed, but not fundamentally limited. It is at the discretion
of the user whether the user scaling should be used or not. When Gain
the resolution remains unaffected in the 16-bit number range.
The value of 1/256 permits gain in the range of 0.0039 ... 255.9960 and thus
gives the user scaling a very high variation range.
4.4.3
Step 3 – Y
In this step, the value Y
into the DAC format, unsigned 16-bit integer. The context of the conversion is
described below:
Table 32: Converting the Data Format
Integer without
Leading Sign
32768
65535
User Scaling
1
is generated with the user scaling. The X
1
.
1
* GainAS / 256 + Offset
Converting the Data Format
2
determined by the configured data format is converted
1
Integer with
Leading Sign
0
−32768
1
−32767
...
...
+32767
AS
Integer with
Leading Sign Bit
undefined
−32767
...
...
0
0
...
...
+32767
Process Image
value serves as the
IN
value is
IN
= 256,
AS
DAC Format
0
1
...
32768
...
65535
Manual
Version 1.3.0
39
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