Analog Value Representation; Introduction; Analog Value Representation For Measuring Range With Simatic S7 - Siemens SIMATIC ET 200S Manual

Analog value representation

4.1

Introduction

Electronic modules with analog outputs
With the electronic module with analog inputs, continuously variable signals, such as those
occurring in temperature measurement and resistance measurement, can be acquired,
evaluated, and converted to digital values for further processing.
4.2

Analog value representation for measuring range with SIMATIC S7

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 of the analog electronic modules.
Table 4-1 Analog value representation (SIMATIC S7 format)
Resolution
Bit number
Significance of the bits
Sign
The sign (S) of the analog value is always in bit number 15:
● "0" → +
● "1" → –
2AI RTD HF analog electronic module (6ES7134-4NB51-0AB0)
Manual, 05/2007, A5E01076876-02
15 14 13 12
S 2 2 2
14 13 12
Analog value
11 10 9 8 7
2 2 2 2 2
11 10 9 8
6 5 4 3
2 2 2 2
7 6 5 4 3
4
2 1 0
2 2 2
2 1 0
23