Query Parameters

Query parameters can be added to the end of the URI, following a '?' character.  Multiple parameters can be specified by separating each parameter with an '&' character.

Each query parameter has the form <name>=<value>, where each value can be specified as a single string value, a simple wildcard by specifying a single asterisk (“*”) as the value, or a Perl regular expression, terminated with a semicolon and enclosed in quotes (|<Perl regular expression>|;”).

The following list describes the optional query parameters:

Query Parameter                    Description

For queries that return a datapoint value, max_age specifies the maximum datapoint age for any returned datapoint values. max_age forces a poll request for the datapoint, if the last datapoint value is older than the time specified by max_seconds. The value cannot be specified as a regular expression.


Specifies the collection of resources found on the page specified by page. Null means one (1).

  • If a snapshot number is not provided with the xs key, the CMS creates a new snapshot of the resources identified by the request path and returns the snapshot number to the client.
  • If a valid snapshot number is provided with the xs key, the page is fetched from the specified snapshot.
  • If an invalid snapshot number is provided with the xs key, an error response is returned.
  • If no page number is specified with the pg parameter, all resources identified by the path parameter are returned.


Specifies the number of resources per page to be used for page requests. Must be an integer greater than zero. Null means no limit.

  • If a pg parameter is specified, but the page size is not specified with the xs parameter, the default is 50. For example: 100
  • Resources may be skipped or duplicated if the requesting application changes the xs value between subsequent requests for different pages.

xs={snapshot_num}Specifies the snapshot number to use when a page is requested using the pg parameter. 
  • When the first of a series of paginated requests is made, the requesting client does not include a snapshot number. When a page is requested using the pg parameter and a snapshot number is not provided with the xs parameter, the requested resources are gathered, sorted in ascending order according to their ID, a new snapshot of the resources is created, and then the snapshot number is returned to the client. 

  • When a paginated response is requested with the pg parameter, if a valid snapshot number is provided with the xs parameter, the CMS fetches the page from the specified snapshot.

  • If an invalid snapshot number is provided with the xs parameter, the CMS returns an error response.