The source can be any tag, calculation or even a constant.  Whatever value is provided here will be the value that is totaled.  In most cases, this will be an analog status or analog input tag, but there are no restrictions on the source.  You might use a digital input to collect a total of equipment running time.  If, for example, you specify a constant value of 1, the totalizer will record the total time that the application is running.

While there is no limitation on what can be used for the source, a totalizer tag will commonly be used with equipment such as a flow meter. Flow meters may provide their values in units of flow per second, flow per minute or flow per hour.  Selecting the correct time scale is of critical importance to collecting an accurate total.

The totalizer tag will record its current total to a log file at the end of each interval specified.  This interval goes by the clock, not by running time.   If, for example, the log interval is set to "Day", the tag's value will be logged at midnight, not at the end of 24 hours of operation.  If the log interval is set to "Hour", the tag's value will be logged each hour on the hour.  Weekly means midnight on Sunday night and Monthly means midnight starting the first day of the month.

You can select whether or not the totalizer should be reset to 0 after its value is logged. 

To allow for a source that does not output an exact 0 when there should be no value to record, you can set a zero cut-off limit.  This value is taken as a range, above and below zero, within which the totalizer takes 0 to be the source's value. 

Note that this is a range above and below zero, not a low value cut-off.  Negative input values are possible from the source tag and are totaled as such.

Text stating what the totalizer tag is totaling (e.g. Gallons, Liters…).

Allows you to specify a tag or calculation to force a reset of the totalizer.  Note that the current value of the tag will always be logged before a reset.  The reset will occur when this input changes from a 0 or false value to a non-zero value.  A change from invalid to non-zero does not cause a reset.