UM-0085-B09
DT80 Range User Manual
Page 135
RG
References are useful in alarms. You can define multiple alarm channels, all of which are testing a reference to a single
measurement against different setpoints.
Note:
Reference channels cannot be added to the On Logger Activation (immediate) schedule, and channels in the On Logger
Activation schedule cannot themselves be referenced.
Calculation
A calculation channel gets its value from a mathematical expression, which may include references to other
measurement channels. The result of the calculation can be logged, have statistics applied to it, and so on – the same as
any other measurement channel.
The configuration builder provides an "expression builder" to make it easier to enter a valid expression. This will appear
when you click inside the
Calculation
field.
Figure 33: Defining a calculation
The three boxes below the calculation entry field list the available maths functions, operators and previously defined
channels that can be referenced. Clicking on any of the items in these boxes will insert it into the calculation entry field.
You can also edit the calculation field manually.
In the above example, the calculation channel is working out the mean of two separate thermocouple readings.
A new feature in the recent version of
dEX
will allow you to self reference a calculation channel. This can be used to
define counter loops in
dEX
without using manual channels. All calculations can be reset with the new reset counter
channel.
The new version of
dEX
now allows the reference the measurement channels from the on logger activation schedule.
Reset Counter
This channel type allows you to reset counter loops that you have setup using the new self referencing option in a
calculation channel .
Figure 34: Reseting counter
