750-563 [2 AO 0/4-20mA / 6-18V DC 16 Bit] • 17
Function
Description
WAGO-I/O-SYSTEM 750
I/O Modules
2.1.1.8.2 Step 2 – Y
1
User Scaling
The value for Y
1
is generated with the user scaling if this is approved through
bit 0 of the register 32. The value X
IN
serves as input value for the user
scaling. For switched-off user scaling, the value X
IN
is transferred unchanged
to Y
1
.
The calculation occurs taking into account the configured data format and the
quality rating of the results is determined by an amplification factor and an
offset.
Configuration of the user scaling
Description
Register 33 - Offset
AS
Offset
Register 34 - Gain
AS
Amplification
factor
Calculation formula:
Y
1
= X
IN
* Gain
AS
/ 256 + Offset
AS
The user scaling serves to adjust a desired process value range to the analog
output range specified through the calibration.
Furthermore, it is possible to map the calibrated 0 ... 20 mA output range so
that the 4 mA analog value is output at a zero process data value with sign and
currents smaller than 4mA can be generated with negative process data values.
The calculation for the user scaling is carried out module-internally in the
32 bit numeric range.
With the use of the user scaling, the required precision of the resolution of the
analog adjusting range is changed, but not essentially limited. It is at the
discretion of the user whether the user scaling should be used or not. With a
GainAS = 256, the resolution remains uninfluenced in the 16-bit wide numeric
range.
The value of 1/256 permits amplifications in the range from 0.0039 to
255,9960 and thus offers the user scaling a very high variation range.
