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Rack 3: ai, Table 8 rack 3: channel field voltage, Table 9 rack 3: normal operating values – Rockwell Automation T8432 Trusted Dual Vdc Analogue Input Module - 60 Channel User Manual

Page 19: Trusted, Module t8432

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Trusted

TM

Module T8432

Issue 16 Apr 10

PD-T8432

19

3.2.3. Rack 3: AI

The AI board returns the engineering units for the associated field input.

Channel Description

1

Field input channel 1 voltage

2

Field input channel 2 voltage

60

Field input channel 60 voltage

Table 8 Rack 3: Channel Field Voltage

The voltage is the median value taken from the triplicated module. Field input current is converted to
voltage using a 250R resistor on a standard field termination assembly (FTA). This AI value may be
used directly or scaled using the IEC1131 TOOLSET conversion tables. The voltage is reported as
1024 counts per volt. To allow easy scaling for 4-20mA inputs, zero volts reports as -1024, one volt
reports as 0, and 5 volts reports as 4096.

Using a 250R field loop configuration the following table represents normal operating values.

Voltage

Current

Engineering Unit

Open

Circuit

-2048

0

0mA

-1024

1

4mA

0

2

8mA

1024

3

12mA

2048

4

16mA

3072

5

20mA

4096

Table 9 Rack 3: Normal operating values