Siemens SIMATIC ET 200C, Manual

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4-50
ET 200C Distributed I/O Station
EWA 4NEB 812 6119-02b
4.4.3 Setting Measurement Type for Analog Module ET 200C;
AI 4
12 Bit
The lower printed-circuit board in the analog module ET 200C;
AI 4
12 Bit accommodates the following module-specific DIL switch
block:
Table 4-23 Module-Specific DIL Switch Block in ET 200C; AI 4 12 Bit
DIL switch block Function Default setting
(as delivered)
S5 Select voltage or current
measurement
OFF
voltage measurement
Select floating or non-floa-
ting measurement
OFF
floating measurement
If you close a DIL switch for current measurement, a shunt resistor
(125 ohms) parallel to the input is activated.
!
Caution
Make sure that this shunt resistor is not in circuit for voltage measurements,
as otherwise the sensor would be overloaded.
The rules for setting the measurement type for the analog module ET 200C;
AI 4
12 bit by means of the DIL switches are as follows:
The shunt resistor parallel to the input of the channel in question must be
activated for measuring currents.
You should always use non-floating measurement by preference, as this
will suppress the effect of severe common-mode disruptions, for example.
When you close the module, make sure that the cover is correctly seated
as damage may occur if the cover is not aligned with the casing.
Basic Requirement
Rules
Mechanical and Electrical Installation