Rockwell Automation T8431 Trusted TMR 24Vdc Analogue Input Module - 40 Channel - Manual (Page 10)

Trusted
TM
Module T8431
Issue 16 Sep 11 PD-T8431 10
1.5. Line Monitoring Thresholds
The module determines the contact state and line fault status by comparing the input voltage 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.
Typical
voltage
threshold
values
Input
Channel
State
Line
Fault
Status
Over-range 6 1
Tmax 6.0
0
High-High 5
T8 2.28
4 or 5 1
T7 2.24
High 4 0
T6 1.82
3 or 4 0
T5 1.79
Normal 3 0
T4 1.52
2 or 3
T3 1.47
0
Low 2
T2 1.12
1 or 2
T1 1.11
Low-Low 1 1
Tmin -0.5V
1
Under-range 0
Table 1 Example Threshold data (24Vdc)
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.