LOYTEC L-STAT - Value Scaling and Stepwidth

L-STAT User Manual 51 LOYTEC
Version 1.0 LOYTEC electronics GmbH
3.4.7 Value Scaling and Stepwidth
The following table gives an overview of how raw Modbus register values are scaled and
which stepwidth is defined for set points.
Physical Value
Unit
Modbus Scaling
A*10^B*(raw + C)
Set Point Stepwidth
Example
A
B
C
raw value
Display value
No Unit
-
1
0
0
1
100
100.0
Temperature
(K)
1
-1
-2740
0,5
2975
023.5
°C
°C
1
-1
0
0,5
235
023.5
°C
°F
1
-1
0
1,0
743
074.3
°F
Flow
m³/h
1
0
0
1
150
150.0
m³/h
l/s
1
-1
0
0,1
417
041.7
l/s
cfm
1
0
0
1
88
088.0
cfm
Pressure
Pa
1
0
0
1
200
200.0
Pa
inWC
1
-3
0
0,01
803
0.803
inWC
Voltage
V
1
-1
0
0,1
240
024.0
V
Percentage
%
5
-3
0
1
9000
045.0
%
Humidity
%RH
5
-3
0
1
9000
045.0
%RH
Amount CO
2
ppm
1
0
0
1
550
550.0
ppm
Note that though a display value or a set point would accept values from 0 to 65535 if
unsigned or -32768 to 32767 if signed the value that is displayed is limited to a range from
-999 to 9999 because of the 4 digit display.
 When a fixed-point number reaches a certain limit where an overflow occurs the
decimal point is shifted rightwards (e.g. 999.9 → 1000).
 Whole number values are preferably displayed with the bigger digits. If an overflow
occurs the number is shifted rightwards (e.g. 999 → 1000).
Table 39: Value Scaling and Stepwidth