LOBOViz CGI Data Service
The LOBOViz server has a public CGI (Common Gateway Interface) that allows remote clients to request and receive LOBO sensor data via HTTP (Hyper-Text Transfer Protocol). This page describes how to access the CGI and retrieve sensor data.
The LOBOViz data CGI for this server is published at the following URL:
CGI Data Query Parameters
Parameters are appended to the URL after a '?' character and are each is subsequently separated by a '&' character.
The following common parameters are supported:
|min_date||first day of data query in format [YYYYMMDD]|
|max_date||last day of data query in format [YYYYMMDD]|
|y||comma-separated list of measurement names for dependent variable(s)|
|data_format||required to be 'text' for text output|
Rather than specific min_date and max_date, there are two alternate date selectors:
|days=n||the most recent n days from today|
|newest=n||the most recent n measurements|
The following are examples of commonly used measurement names for the 'y=' independent variable list:
|cdom||colored dissolved organic matter|
|voltage||power supply voltage|
The names of other measurement items and node identifiers can be found by examining the URL after producing a plot then using the Permalink button. Users with full management access can list all items in the system configuration tools. Note that only one node may be selected per data download.
As mentioned above for measurement names; use the Permalink URL from a plot to determine the numeric site identification for use in the value of a "node=" parameter. Note that unlike data plots which can display multiple sites simultaneously, data download is one site at a time.
CGI Data Result Format
The data are returned as tab-separated text representations of numeric values. The first line of the returned data is a header of tab separated names and units for each data column. Each subsequent line displays local date/time in format [YYYY-MM-DD hh:mm:ss], followed by a numeric value for each requested measurement.
For example, if you want to retrieve salinity and nitrate for July 28, 2016 to August 2, 2016 (inclusive) at the example site the URL would be:
Click the above URL to see the tab-separated text data returned by the server.
Another example, the 12 most recent temperature measurements:
Any programming language with HTTP support can be used to directly access the LOBO data CGI and process the returned sensor measurements. Alternately, an HTTP utility such as wget can be invoked to retrieve the data and save to local file for later processing.