ABB REB650, Technical Manual

Page: 244 / 504

zero point clamping might be overridden by the zero point clamping used for the
measurement values within CVMMXN.
Continuous monitoring of the measured quantity
Users can continuously monitor the measured quantity available in each function block
by means of four defined operating thresholds, see figure
103 . The monitoring has two
different modes of operating:
• Overfunction, when the measured current exceeds the High limit ( XHiLim ) or High-
high limit ( XHiHiLim ) pre-set values
• Underfunction, when the measured current decreases under the Low limit
(
XLowLim ) or Low-low limit ( XLowLowLim ) pre-set values.
X_RANGE is illustrated in figure 103 .
en05000657.vsd
X_RANGE= 1
X_RANGE = 3
X_RANGE=0
Hysteresis
High-high limit
High limit
Low limit
Low-low limit
X_RANGE=2
X_RANGE=4
Y
t
X_RANGE=0
IEC05000657 V1 EN
Figure 103: Presentation of operating limits
Each analog output has one corresponding supervision level output (X_RANGE). The
output signal is an integer in the interval 0-4 (0: Normal, 1: High limit exceeded, 3: High-
high limit exceeded, 2: below Low limit and 4: below Low-low limit). The output may
be connected to a measurement expander block (XP (RANGE_XP)) to get
measurement supervision as binary signals.
The logical value of the functional output signals changes according to figure 103 .
The user can set the hysteresis ( XLimHyst ), which determines the difference between
the operating and reset value at each operating point, in wide range for each measuring
channel separately. The hysteresis is common for all operating values within one channel.
Section 12
1MRK 505 277-UUS C
Monitoring
238
Technical Manual