Fcal Units

Controls: Options >> Frequency Counter >> Fcal >> Units
Macro: FcalUnits

When a Calibration Table is active that uses Unit:DegC or Unit:DegF in its header, the Units button is enabled and will show Celsius or Fahrenheit, respectively. When Fcal is active the Frequency Counter will likewise show 'C' or 'F' after displayed values.

Toggling the Units button will convert between Celsius and Fahrenheit.

Although this option is only available when using a Calibration Table, you can use it with linear sensors like the LM335, or with a calibrated diode sensor. Just load the special LinearC.TBL "calibration" table, which simply passes values through unchanged but has Unit:DegC set in its header.

Alternatively, if you have created your own calibration table in degrees Fahrenheit, or you are using a linear temperature sensor and want to enter Fahrenheit for Fcal High Set and Fcal Low Set, you can load LinearF.TBL. This is identical to LinearC except it uses Unit:DegF. The Units button will then read and operate correctly.

Note that toggling Units changes the Frequency Counter display value, but it does not change Fcal High Set or Fcal Low Set.

Macro Notes:

The Fcal dialog does not need to be open to change the Fcal Units state. However, since separate tables are maintained for each Trigger Source channel and valid Frequency Counter mode (Hertz, RPM, and msec), you must make sure the desired source and mode are set in order to change the proper Units state.

FcalUnits=1 toggles the Units state On, which switches between Celsius and Fahrenheit. For the standard thermocouple tables that come with Daqarta, this will change from Celsius to Fahrenheit. However, if you have created a custom table of Fahrenheit values and used Unit:DegF in the header, this will change from Fahrenheit to Celsius.

FcalUnits=0 restores Units to the default state, and FcalUnits=x toggles between the two states.

You can read FcalUnits to determine the current state. A value of 0 indicates that no table has been loaded; otherwise, 1 is Celsius and 2 is Fahrenheit, regardless of the original units of the table. For example, if the table specifies DegC then 1 means the Units button is up, in the default Celsius state, and 2 means it is depressed to Fahrenheit. But if the table uses DegF, then 2 means the Units button is in the default up state for Fahrenheit and 1 means it is depressed for Celsius.

See also Fcal Dialog, Frequency Counter