Field Device Trend History

When Historical point data is stored in a Remote Terminal Unit (RTU) data logger, this application enables you to configure the system such that it sends the data to the Historical database.

When analog collect records are configured with the collect type "device based history", Omnicomm sends the Historical data collected from the RTU to a spooler, which in turn calls a stored procedure in the Historical database that adds data to the TimeSeries database. This provides Controllers with immediate access to the data for the purposes of trending. The flow of data is illustrated below.

If by chance an analog record either doesn't have an associated collect record, or the analog collect record's collect type is something other than "device based history", the system does not send the data to the TimeSeries database. Instead, the system generates an alarm against the remote. The alarm message takes the following format:

Device Based History error - point <NameOfRecord> <AlarmMessage>

However, if an analog record does not have an associated collect record, the system logs data to the collectLog.log file.

Note: The supported data type for device-based history is float. Since the float data type has six to nine digits of precision, it can exactly represent any number up to six significant digits. The float data type may or may not exactly represent a number with seven to nine significant digits depending on the specific value. The float data type will not exactly represent a number with more than nine digits of precision. For more information, refer to Microsoft documentation on floating point precision.