Campbell Scientific CR1000 Measurement and Control System - Manual (Page 380)

Section 8. Operation
380
Table 94. DataQuery API Command Parameters
uri
Optional. Specifies the URI (p. 470) for data to be queried. Syntax: dl:tablename.fieldname . Field
name is optional. Field name is always specified in association with a table name. If field name
is not specified, all fields are collected. If
fieldname refers to an array without a subscript, all
values associated with that array will be output. Table name is optional. If table name is not
used, the entire URI syntax is not needed as
dl (CR1000) is the default data source.
mode
Required. Modes for temporal-range of collected-data:
most-recent returns data from the most recent number of records. p1 specifies maximum number
of records.
since-time returns most recent data since a certain time. p1 specifies the beginning time stamp
(see Time Syntax (p. 375) section).
since-record returns records (p. 463) since a certain record number. The record number is specified
by p1. If the record number is not present in the table, the CR1000 will return all data starting
with the oldest record.
date-range returns data in a certain date range. The date range is specified using p1 and p2 . Data
returned include data from date specified by p1 but not by p2 (half-open interval).
backfill returns data stored since a certain time interval (for instance, all the data since 1 hour ago).
The interval, in seconds, is specified using p1 .
p1
Optional. Specifies:
• maximum number of records ( most-recent )
• beginning date and/or time ( since-time , date-range ). See Time Syntax (p. 375) for
format.
• beginning record number ( since-record )
• interval in seconds ( backfill )
p2
Optional. Specifies:
• ending date and/or time ( date-range ). See Time Syntax (p. 375) for format.
format
Optional. Specifies the format of the output. If this parameter is omitted, or if the value is html,
empty, or invalid, the output is HTML.
format Option Data Output Format
Content-Type Field of
HTTP Response Header
html HTML text/html
xml CSIXML text/xml
json CSIJSON application/json
toa5 TOA5 text/csv
tob1 TOB1 binary/octet-stream
Note: When json is used, and the web server has a large data set to send, the web server may
choose to break the data into multiple requests by specifying a value of true for the more flag in
the CSIJSON output. The more flag is not shown if a complete data set is first returned.
Examples:
http://192.168.24.106/?command=DataQuery&uri=dl:MainData&mode=da
te-range&p1=2012-09-14T8:00:00&p2=2012-09-14T9:00:00
Response: collect all data from table MainData within the
range of p1 to p2*