7 i/o compound modules - analog i/o, 1 representation of analog values, I/o compound modules − analog i/o – Lenze I/O system 1000 System Manual User Manual
Page 110: Representation of analog values, Product description
Product description
I/O compound modules − analog I/O
Representation of analog values
l
110
EDSIO1000 EN 7.0
3.7
I/O compound modules − analog I/O
3.7.1
Representation of analog values
Analog values can only be processed in a binary form. For this, the analog module converts
each process signal into a digital form and passes it on as a 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
Valency
Sign bit
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
12 bits + sign bit
Sign bit
Measured value
0
0
0
15 bits + sign bit
Sign bit
Measured value
Resolution: In the case of a resolution of 12 bits plus sign bit, the lower−order digits that are
not used (3 bits) are written to with "0".
Sign bit: Bit 15 = "0"
®positive value; bit 15 = "1" ®negative value.
Response in the event of an error: If a measured value exceeds the overrange or falls below
the lower range, the following value is output:
Measured value > overrange
®32767 (7FFF
h
)
Measured value < lower range
®−32768 (8000
h
)
If a parameterisation error occurs, the measured value 32767 (7FFF
h
) is output.