Limit Value Supervision - ABB RELION REX640 Technical Manual

1MRS759142 C
3.15.4.2
REX640
Technical Manual
"100". These settings allow the input values to be scaled as a ratio of the resistance
range.
AI_VAL
Value maximum
100
Value unit
"Dimensionless"
Value minimum
0
100Ω
Input minimum
GUID-CA5681A0-CD3D-4DC9-A961-CD5D0C9D9B43 V1 EN
Figure 56: Output as a ratio of the resistance range
The output scaling function:
Input maximum Input minimum
−
k =
Value maximum Value minimum
−
GUID-DED17E54-7FDF-4D3A-BF56-6371FD093387 V1 EN
f k Value minimum Input minimum
= − ⋅
GUID-9F09BD7F-EE3B-449A-9419-21FB21EA3EC2 V1 EN
Input f
−
AI VAL
_
=
k
GUID-29BC674C-2C9F-4052-95A9-53BFFB4B3C92 V1 EN

Limit value supervision

All the measurement inputs have individual limit supervision modules that operate
similarly as in the measurement functions. The measured values are compared against
their set value limits. The limit supervision outputs are HIGH_ALARM, HIGH_WARN,
LOW_WARN and LOW_ALARM.
When an output is scaled, Value maximum and Value minimum are the range limits to
which the output value is limited or scaled. Hysteresis is added to the range limit
values so that the output value is allowed to slightly exceed or go below the limit value
before being treated as out of range.
The pre-defined hysteresis values are set based on the set Value unit.
Input mode
"Resistance"
+
Section 3
Basic functions
Input
1600Ω
Input maximum
(Equation 3)
(Equation 4)
(Equation 5)
165