ABB REC650 ANSI Technical Manual page 448

Section 12
Monitoring
Y
Value Reported
(1st)
IEC99000529 V1 EN
Figure 205: Magnitude dead-band supervision reporting
442
Magnitude dead-band supervision
If a measuring value is changed, compared to the last reported value, and the change is
larger than the ±ΔY pre-defined limits that are set by user (UDbRepIn), then the measuring
channel reports the new value to a higher level. This limits the information flow to a
minimum necessary. Figure
supervision. The picture is simplified: the process is not continuous but the values are
evaluated with a time interval of one execution cycle from each other.
Value Reported
Y3
Y2
DY
DY
Y1
After the new value is reported, the ±ΔY limits for dead-band are automatically set around
it. The new value is reported only if the measured quantity changes more than defined by
the ±ΔY set limits.
Integral dead-band reporting
The measured value is reported if the time integral of all changes exceeds the pre-set limit
(XDbRepInt), figure 206, where an example of reporting with integral dead-band
supervision is shown. The picture is simplified: the process is not continuous but the
values are evaluated with a time interval of one execution cycle from each other.
The last value reported, Y1 in figure
A difference is calculated between the last reported and the newly measured value and is
multiplied by the time increment (discrete integral). The absolute values of these integral
values are added until the pre-set value is exceeded. This occurs with the value Y2 that is
205 shows an example with the magnitude dead-band
Value Reported
DY
DY
DY
DY
206 serves as a basic value for further measurement.
1MRK 511 287-UUS A
Value Reported
t
99000529.vsd
Technical manual