Advanced Column Descriptions

Hover over column titles to display instructions for the column in the worksheet.

Min Freq⁺: The minimum frequency of historization for PortIO tags. At least one point will be historized at intervals based on the frequency specified, even if the value does not change between recorded points. The default is 600 seconds. If set to 0 and if the Max Freq > 0, data will only be written if the values changes or if other criteria trigger a write, such as a bad quality point.

Max Freq⁺: The maximum frequency of historization for PortIO tags. For an OPC tag, this is the update frequency used to pull or receive data from the OPCDA. The default is 0. MaxFreq < 0 means that the tag will not be added to the OPC server, but will remain active and data can be assigned to the tag.

Process Name/ID: This is the process name that the tag has been assigned to.  Double-click on the cell  to open up the process tree.

Tag Alias: Used if a different tag name needs to be displayed in the Tag Browser. Everywhere else, the Tag Name will be displayed.

Percent Dev. Deadband⁺: With OPC tags, this value is the relative amount a tag must change for it to be historized. If the Data Min and Data max fields are filled in, then the value must change by more than (Data Max – Data Min) * PercDeadBand/100 before a value is historized.  The default is 0.01.

OPC Tag Name/Loop Num: This is the OPC recognized tag name or item.  This allows the Tag Name and the actual OPC tag name to differ. If the field is not filled out, then the OPC recognized item name must be in the Tag Name field and the PortIO must be configured to not use this field. This field is not required, but is a default for PortIO.

Scale A and Scale B *⁺: These parameters are used to modify a value as it is pulled from the historian. The equation is : Returned Value = A * Historized Value + B. This does not affect the value that is historized, just the value that is returned to the client. This is used for unit conversions, converting values from lb./hr. to 1000lb/hr., etc. The default is 1.

Tag Style*⁺: This the style of how the tags is interpolated. There are four options: continuous, state1, state2 or lab.

Continuous: The tag will be interpolated continuously between points using linear interpolation.

State1: The tag will be interpolated like a state variable or square wave, flat lining the tag's value from one point to the next.

State2: The tag will be interpolated as a state variable or square wave, but in the trend, it will be treated as a text tag with a vertical line for each value.

Lab: The value will be interpolated as a manual point or square wave, the draw mode will be square wave, there will be no line in the trend and dots will be displayed at each point.

OPC Group Num / dsparam3: For OPC tags, this will assign the tag to a group number when connecting or adding the tags to the OPC. 

OPC Number / dsparam2: If the PortIO is set up connect to two different OPCs to collect tag data, this field determines which OPC each tag will be collected from.

Data Min and Data Max: With OPC tags and Percent Deadband: if both Data Min and Data Max are defined, the percent dead banding is not done on a relative change, but based on the percent deviation times the span defined by Data Min and Data Max. A tag must change by more than that value for it to be historized.

Filter Min: With RollUp server data, any value below is this ignored in the calculation. This is also used for the Optional Parameter of ZeroCutOff.

Filter Max: With RollUp server data, any value above this parameter is ignored in the calculation.

Write Location: For PortIO sources, this determines whether data will be written to PARCHistory, SQL server or both.  The default is PARChistory.

Read Location: This sets whether data will be read from PARCHistory or SQL.  The default is PARCHistory.

Optional Parameters: Sets the ZeroCutOff for a tag. The format for zerocutoff is: “ZeroCutOff=True;” or “ZeroCutOff=True,False;”. There must be a “;” at the end of each parameter.  The First part, if set to true, will set the tag back to its previous value if its value goes below DataMin. The second part is optional and will not write out a tag’s value if its actual value goes to zero when set to False. The default is “ZeroCutOff=False,True;”.

Backfill Tag: Uses a full UTag name to backfill data for another tag with the PARChistory Importer application. For example, if a site is transitioning to a new data historian, an old tag could be used to backfill a tag in the new historian.