3.2 Analog value
Analog values are exclusively processed in a binary format. For this the analog module
transforms every process signal into a digital value and transfers this as word.
Resolution
Analog value
High byte (byte 0)
Low byte (byte 1)
Bit number
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Value
SG
2
14
2
13
2
12
2
11
2
10
2
9
2
8
2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
12Bit+sign
SG
Measuring value
0
0
0
15Bit+sign
SG
Measuring value
With a resolution of 12bit plus sign bit, the not used low value positions (3bits) are filled
with "0".
Here it is essential:
n
Bit 15 = "0":
à
positive value
n
Bit 15 = "1":
à
negative value
As soon as a measured value exceeds the overdrive region respectively falls below the
underdrive region, the following value is issued:
n
Measuring value > end of overdrive region:
32767 (7FFFh)
n
Measuring value < end of underdrive region:
-32768 (8000h)
At a parameterization error the value 32767 (7FFFh) is issued.
3.3 Measuring ranges and function numbers
In the following there are the measuring ranges with function number listed, which were
supported by the corresponding analog module.
The here listed formulas allow you to transform an evaluated measuring value (digital
value) to a value assigned to the measuring range and vice versa.
Representation of analog
values
Resolution
Sign bit (SG)
Behavior at error
General
VIPA System SLIO
Analog Input
Measuring ranges and function numbers
HB300 | SM-AIO | | en | 17-05
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