ABB REG650 Technical Manual page 420

Section 14
Monitoring
Y
Value Reported
(1st)
IEC99000529 V1 EN
Figure 195: Magnitude dead-band supervision reporting
414
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 (XZeroDb), then the
measuring channel reports the new value to a higher level, if this is detected by a new
measured value. This limits the information flow to a minimum necessary. Figure
shows an example with the magnitude dead-band 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 196, 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
measurement. A difference is calculated between the last reported and the newly
measured value and is multiplied by the time increment (discrete integral). The
Value Reported
DY
DY
DY
DY
196 serves as a basic value for further
1MRK 502 043-UUS B
195
Value Reported
t
99000529.vsd
Technical Manual