ABB AC500 PLC - Connection of Active-type Analog Sensors (Voltage) with no Electrically Isolated Power Supply

The following measuring ranges can be configured Ä Chapter 1.5.2.2.1.6 “Parameterization”
on page 463
Ä Chapter 1.5.2.2.1.9 “Measuring Ranges” on page 468
Current 0 mA...20 mA 1 channel used
Current 4 mA...20 mA 1 channel used
The function of the LEDs is described under Displays Ä Chapter 1.5.2.2.1.7 “Diagnosis”
on page 466.
Unused input channels can be left open-circuited, because they are of low resistance.
Connection of Active-type Analog Sensors (Voltage) with no Electrically Isolated Power Supply
UP
ZP
1.0
I0-
1.1
I1-
1.8
UP
1.9
ZP
PTC
2.0
I0+
2.1
I1+
2.8
UP
2.9
ZP
0 ... 10 V
AGND
Fig. 37: Connection example
CAUTION!
The potential difference between AGND and ZP at the module must not be
greater than 1 V, not even in case of long linesFig. .
If AGND does not get connected to ZP, the sensor current flows to ZP via the
AGND line. The measuring signal is distorted, as a very low current flows over
the voltage line. The total current through the PTC should not exceed 50 mA.
This measuring method is therefore only suitable for short lines and small
sensor currents. If there are bigger distances, the difference measuring method
has to be preferred.
The following measuring ranges can be configured Ä Chapter 1.5.2.2.1.9 “Measuring Ranges”
on page 468
Voltage 0 V...10 V 1 channel used
Voltage -10 V...+10 V *) 1 channel used
*) if the sensor can provide this signal range
The function of the LEDs is described under Displays Ä Chapter 1.5.2.2.1.7 “Diagnosis”
on page 466.
In order to avoid error messages or long processing times, it is useful to configure unused
analog input channels as "unused".
Device Specifications
I/O Modules > Analog I/O Modules
2019/04/17 3ADR010121, 13, en_US 459