Table 54: Settings for RTD analog input limit value supervision
Function
Settings for limit value supervision
RTD analog input
Out of range
Value maximum
High-high limit
Val high high limit
High limit
Val high limit
Low limit
Val low limit
Low-low limit
Val low low limit
Out of range
Value minimum
When the measured value exceeds either the
Value maximum setting or the Value
minimum setting, the corresponding quality is set to out of range and a maximum
or minimum value is shown when the measured value exceeds the added hysteresis,
respectively. The hysteresis is added to the extreme value of the range limit to allow
the measurement slightly to exceed the limit value before it is considered out of
range.
3.13.2.8
Deadband supervision
Each input has an independent deadband supervision. The deadband supervision
function reports the measured value according to integrated changes over a time
period.
Figure 46: Integral deadband supervision
The deadband value used in the integral calculation is configured with the
Value
deadband setting. The value represents the percentage of the difference between
the maximum and minimum limits in the units of 0.001 percent * seconds. The
reporting delay of the integral algorithms in seconds is calculated with the formula:
t s
Y
( )
(
)
=
−
⋅
Value maximum
Value minimum
deadband
s
100000
∆
(Equation 4)
1MRS757644 H
Basic functions
620 series
Technical Manual
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