ABB RELION REX640 - Page 178

linear curves. The knee points are defined by parameters Input knee point 1-4 and
Value knee point 1-4 .
Example 1: VMMXU1 to mA output
VMMXU1
U3P
BLOCK
HIGH_ALARM
HIGH_WARNING
LOW_WARN
LOW_ALARM
U12-kV
U23-kV
U31-kV
U_INST_A
U_INST_B
U_INST_C
Slot# – mA#
AO_VAL
AI_VAL
HIGH_ALARM
HIGH_WARN
LOW_WARN
LOW_ALARM
Figure 73: Application example for VMMXU1 to mA output
The measured phase-to-phase voltage from VMMXU is connected to
AO_VAL. Input maximum value is set to "24" (kV) and Input minimum value is
set to "18" (kV). The input unit is not significant as long as the value range is
in the same scale.
Value maximum is set to "20" mA and Value minimum to
"4" mA. Num of knee points is set to "0".
Value minimum
Value maximum
20
4
AO_VAL
Output [mA]
Input minimum
2418
12
Input maximum
21
Figure 74: Scaling of AO_VAL to mA output
Example 2: mA input to mA output
Slot# – mA1
AO_VAL
AI_VAL
HIGH_ALARM
HIGH_WARN
LOW_WARN
LOW_ALARM
Slot# – mA2
AO_VAL
AI_VAL
HIGH_ALARM
HIGH_WARN
LOW_WARN
LOW_ALARM
Figure 75: Application example for mA input to mA output
Basic functions
1MRS759142 F
178 REX640
Technical Manual