The History Recorder microblock records a current and previous value from a microblock in a control program. You determine when the value is recorded. The Properties page shows the current and previous values (Current cycle and Previous cycle), and the time of day and the date when the recordings were made.
The microblock's analog input receives the value that is to be recorded. When the rec input is on, the microblock transfers the current value of its input to its primary output, and the prior output value is transferred to the prev output. The value is recorded only once while the rec input is on.
For example, if the microblock is used to record the zone temperature, and the rec input remains on while the temperature changes, only the temperature that was current at the time the rec input turned on will be recorded.
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