Line monitoring thresholds, Table 1 example threshold data (4-20ma), Trusted – Rockwell Automation T8433 Trusted TMR Isolated 4-20 mA Analogue Input Module - 20 Channel User Manual

Page 12: Module t8433

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Trusted

TM

Module T8433

Issue 11 Apr 10

PD-T8433

12

1.5. Line Monitoring Thresholds

The module determines the contact state and line fault status by comparing the input current level to
four user programmed thresholds and two fixed (minimum and maximum) thresholds. Hysteresis is
provided on the thresholds by up-scale and downscale values, corresponding to the thresholds for
increasing and decreasing values respectively.

Default

threshold values
(mA)

Input
Channel
State


Line Fault
Status

Over-range

6

1

Tmax

24.0

High-High

5

0

T8

18.25

4 or 51

T7

17.75

High

4

0

T6

13.25

3 or 4

0

T5

12.75

Normal

3

0

T4

9.75

2 or 3

T3

9.25

Low

2

0

T2

6.25

1 or 2

T1

5.75

Low-Low

1

1

Tmin

-2.0

Under-range

0

1

Table 1 Example Threshold data (4-20mA)

Default threshold values used for non line monitored inputs are as follows (in raw units)

Default = 448,576,1344,1472,2240,2368,3520,3648.

1

The channel state value returned is dependent on the previous state value. If the input level is

increasing then the lower state value will be returned. If the input level is decreasing the higher state
value will be returned.

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