Analog electronic modules
4.3 Basics of Analog Value Processing
ET 200S
4-14
Manual, Edition 10/2005, A5E00514527-01
Output modules for voltage and current: 1 V to 5 V; 4 mA to 20 mA
Table 4-24 SIMATIC S7 format: Output ranges 1 V to 5 V; 4 mA to 20 mA
Units
Output range
Up to 5 V
Output range
up to 20 mA
Decimal
Hexadeci
mal
Range
0
0
> 32511
> 7EFF
H
Overflow
5.7000
:
5.0002
22.8100
:
20.0005
32511
:
27649
7EFF
H
:
6C01
H
Overshoot range
5.0000
:
1.0000
20.0000
:
4.0000
27648
:
0
6C00
H
:
0
H
Rated range
0.9998
:
0
3.9995
:
0
-1
:
-6912
FFFF
H
:
E500
H
Undershoot range
0
0
< -6913
< E4FF
H
Underflow
4.3
4.3
Basics of Analog Value Processing
4.3.1
Connecting measuring sensors
Introduction
You can connect different measuring sensors to the analog input modules, depending on the
type of module involved:
•
Voltage sensor
•
Current sensors as:
–
2-wire transducer
–
4-wire transducer
•
Resistance-type sensor
In this chapter you will find out how to connect the measuring sensors and what to watch for
when doing so.
Lines for analog signals
You should use shielded and twisted-pair lines for the analog signals. This reduces the effect
of interference. You should ground the shield of the analog lines at both ends of the line. If
there are differences in potential between the ends of the line, a compensating current flows
via the shield that can interfere with the analog signals. If this is the case, you should only
ground the shield at one end of the line.