2AO I HF analog electronic module (6ES7135-4MB02-0AB0)
Manual, 04/2007, A5E01076972-01
17
Analog value representation
4
4.1
Introduction
Electronic modules with analog outputs
With the electronic modules with analog outputs, digital values set by a controller can be
converted to a corresponding analog signal (current) in an analog output module and used to
control suitable actuators (setpoint input for speed controllers, temperature controllers and
similar).
4.2
Analog value representation for measuring ranges with SIMATIC S7
with 2AO U HF
Analog value representation
With the same nominal range, the digitized analog value is the same for input and output
values. Analog values are represented in two's complement.
The following table shows the analog value representation for the analog electronic modules.
Table 4-1
Analog value representation (SIMATIC S7 format)
Resolution
Analog value
Bit number
15 14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Significance of the bits
S
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
Sign
The sign (S) of the analog value is always in bit number 15:
●
"0" → +
●
"1" → –
