OMC-042 / 043 / 044 Data loggers
Users
’ manual
page 41
Choose which aggregation results you want to record, being average, minimum, maximum, standard
deviation and/or gust. A gust is the highest 3 sample average occurred in an aggregation period.
Calculation Channels (OMC-043/044 only)
Besides the different Physical channels the data logger contains, it also has a number of “calculation
channels”. These are very powerful virtual channels. i.e. they are not real physical input channels, but
virtual channels to hold i.e. an in-between result, for a complex calculation. It allows the user to perform
complex calculations in order to transform the electrical signal from the input to a real life value. It enables
the user the connection of a very wide range of sensors, including non-linear ones. All kind of
mathematical functions can be used inside a calculated channel. The section covers how to use
calculated channels and gives you a real-life example. Calculated channels are found in the configuration
setup (below)
A calculated channel can be used to derive a meaningful engineering value from sensed input values
using mathematical operators, parentheses and functions (a/o cos, sin, atan2, ln, sqrt).
Syntax
Within the data logger each sensed/calculated parameter/channel has a parameter code chosen by the
user (e.g. TEMPC for a temperature in Celsius,
Note
: codes should not contain any spaces or signs).
These parameter codes can be used in equations by preceding them with a colon (:). When calculating,
the parameter codes will be substituted with the last recent measured values.
It’s possible to use multiple
parameters in one equation. The order of operations (add, subtract, divide and multiply) is the same as
when using a calculator and parentheses can be used to group operations together if you are confused
about the order of operation.
Functions
Besides using simple operators, mathematical functions can be used as well. The syntax of a function is:
<function_name>(<arguments>).
Example: sin (x) (calculates the sinus of x)
Configuration setup
[0] Exit
[1] General settings >> OBSC6721BK
[2] Modem settings
[3] NTP time update >> Used
[4] Alarm SMS >> Not used
[5] SMS commands >> Not used
[6] Internal sensors >> Internal
[7] Analog sensors >> Potmeter
[8] Digital sensors >> Digital pulse
[9] Network signal sensor >> Not used
[A] Serial port >> Not used
[B] Accessory port >> Not used
[C] Derived channels >> Used
[D] DTU connection >> Not used
[E] Email output >> Not used
[F] FTP output >> Not used
[G] TCP output >> TCP
[-] HTTP output >> N/A
>
Derived channels
[0] Exit
[1] Aggregations >> Used
[2] Calculations >> Used
>