Datalogger Program Intervals

There are two types of intervals written into the datalogger program which affect the availability and collection of data:

• Program Execution Interval – The execution, or scan, interval determines how often the datalogger carries out the instructions in the datalogger program. It is specified in seconds and determines the fundamental rate at which data is available. In typical programs the sensor readings are taken at this rate and the values are stored in corresponding Input Locations or variables. This execution interval is the fastest that data measurements can be updated and data stored. (Depending on how the program is written, sensor readings may occur at specified intervals and not on every program execution.)

• Table Storage Interval – Most data tables are set up to store data records at regular intervals. The data record consists of a record number and time stamp, followed by the output processing (i.e., sample, average, min, max, etc.) of the variable values. This interval must be a multiple of the program execution interval or storage intervals will be skipped. For example, if the program execution interval is 5 seconds and the table interval is set to 3 seconds, there will only be an entry in the table every 15 seconds. The interval specified determines the fastest rate the server can collect new data that is stored to the datalogger final storage memory.