ABB ScreenMaster RVG200 Operating Instructions Manual page 133

ScreenMaster RVG200
Paperless recorder
Individual recording channel signals, analog and digital sources and 7-digit totalizer values can be
combined in a math equation to produce a customized recording channel or retransmission source.
Typical examples include adding / subtracting the values of a number of analog sources together to form
one recording channel.
More complex blocks can also be created to determine relative humidity.
Digital signals can be used in math equations to enable / disable the output when certain conditions are
true.
This is an example of a typical math equation:
= +
mb1 aiA1 52.4 Log(aiA2) diD2
Where:
mb1 = Math result (can be assigned to, for example, recording channels, other math equations)
aiA1 = Analog source
52.4 = Constant (can be any numerical value of up to 3 decimal places)
Log(aiA2) = Function – see Table 7.5, page 132
diD2 = Digital source
Note.

Operators are evaluated according to standard operator precedence; therefore, the above
equation is evaluated as aiA1 + (52.4 x Log(aiA2)) – diD2.

Functions may be nested within other functions.

Digital signals are evaluated as 0 (inactive) and 1 (active), therefore in the example:
mb2 = (aiA1 + aiA2) x diD1
the sum of (aiA1+ aiA2) is set to zero if the digital input diD1 is also zero.
OI/RVG200-EN

–
7 Configuration
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