ABB REO 517, Руководство по применению

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341
Monitoring of AC analog measurements
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Users can select between two types of dead-band supervision:
• Amplitude dead-band supervision (ADBS).
• Integrating dead-band supervision (IDBS).
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If a measuring value is changed, compared to the last reported value, and the change is
larger than the +/-
∆
Y predefined limits that are set by user, then the measuring channel
reports the new value to a higher level, if this is detected by a new measuring sample.
This limits the information flow to a minimum necessary. Figure 183 shows an example
of periodic reporting with the amplitude dead-band supervision. The picture is simpli-
fied: the process is not continuous but the values are evaluated with a time interval of
one second from each others.
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After the new value is reported, the +/-
∆
Y 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 +/-
∆
Y set limits.
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The measured value is reported if the time integral of all changes exceeds the pre-set
limit (figure 184), where an example of reporting with integrating dead-band supervi-
sion is shown. The picture is simplified: the process is not continuous but the values are
evaluated with a time interval of one second from each other.
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