Extension Query Parameters

Use these parameters in your extension query.

Parameter Description
Tag Source Specify a tag source.
Tag Allows to browse and select a tag.
Authentication Select how to authenticate when you submit a query:
  • Logon User Token: Uses the user login token for authentication.
  • Provide in Query Parameters: Uses User Name and Password input fields for authentication.
  • Use Data Source Credentials: Uses the write credentials configured in the data source for authentication.
  • Anonymous: No authentication.
Tag Display Format Select a display format for the tag name.
Sampling Mode Select a sampling mode for retrieving data.
Calculated Mode If the sampling mode is Calculated, specify the calculation mode.
Start Time Select the calendar icon to set a start time.
Duration Enter the duration.
End Time Select the calendar icon to set an end time.
Sampling Time Enter the sampling time.
Sampling Count Enter the sampling count.
Sampling Direction Direction of sampling, whether forward or backward.
Note: This parameter is used only when the sampling mode is RawByNumber. You must also specify the sampling count for this parameter.
Show Comments Select/Clear the check box to show/hide comments.
Sort By Defines how a Data Distributor extension query result-set should be sorted. You must enter the syntax, which is a comma-separated list of Data Distributor extension query fields. The result set is sorted by the fields specified in the list, in the given order.
Examples:
  • timestamp,name means to sort by timestamp first, then by name.
  • name,timestamp means to sort by name first, and then by timestamp.

Each field in the syntax can optionally have a suffix of a plus + or minus - symbol to indicate the sorting order for that field.

For example, timestamp-,name+ means to sort by timestamp first in a descending order, then by name in an ascending order.

The default sorting order for timestamp is descending, and rest of the fields are ascending.

Each field in the syntax can be denoted either by its full output field name, or a built-in one letter identifier. For example,
  • t for timestamp
  • n for tag name
  • v for value
  • q for quality

If you do not enter a syntax, or left this field blank, then the behavior is to sort by timestamp descending.

Currently, for auto sync queries, the sorting order only applies to the initial result set and not any subsequent new rows to the result set.