Numbers - mathematical channels
The mathematical channels are used for calculating functions using mathematical operations. In
the simplest form, a number is calculated by means of a sum of products (sum of multiplications).
RESULT = (A * B * ... * C) + ... + (D * E * ... * F)
e.g.
RESULT = (A * B)
RESULT = (A * B) + (C * D) + E
You can also use integer division (“/” symbol) or a division remainder (“
mod
” symbol)
e.g.
RESULT = (A * B/ C)
RESULT = (A mod B) + (C * D * F)
Channel value modifiers.
Channels used for mathematical operations may be scaled
before the operation is defined. You may divide by 1, 10, 100 or
1000 (the fraction remainder is rejected). You may also choose
to use the
raw
value with no modification.
Raw applies to the
voltage from analogue inputs, for example, where it is a value
from an ADC converter with a range of [0..1023].
Calculating the sum of currents of 3 PMU current outputs
Three channels are given:
c_pmu_o1.current,
c_pmu_o2.current,
c_pmu_o3.current. Each channel
contains the current usage of a PMU output, and these
messages are sent from the PMU.
Let’s assume that we want to a have a result with an
accuracy of up to 0.01 A.
The following formula should be used:
n_c = (o1.current*100 + o2.current*100 + o3.current*100)
where the point should be “moved” by two decimal places
to the left.
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