Instructions

UM-0085-B09 DT80 Range User Manual Page 170
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Customising the Classic Interface
This section describes some of the technical features of the DT80 web interface. These allow advanced users to replace
the built-in web interface with a customised web user interface.
Web Application Programming Interface (API)
The DT80 provides an application programming interface (API) so that you can build custom web pages that can view
and display data from the logger. The API consists of a set of server-side include (SSI) directives. SSI directives are
placed in HTML pages, and evaluated on the logger when the HTML page is requested. HTML pages that contain SSI
directives are known as SHTML pages, and typically have a .shtml file extension.
When an SHTML page is requested, it is scanned by the web server (logger) for these directives. Once found, the logger
interprets the directive and performs the required action. The output is then sent as part of the response back to the web
browser.
Server-Side Include (SSI) Directives
An SSI directive consists of a special sequence of characters which is placed within an HTML page. The format is as
follows:
<!--#directive attribute="value" attribute="value" … -->
where:
•
<!--# and --> are the opening and closing identifiers that must be specified when applying an SSI directive.
• directive is the name of the directive to be executed.
• attribute is the name of an attribute, and value is the value it is set to. Each SSI directive has a set of valid
attributes that can be specified to control the operation of the directive. One or more attribute-value pairs can be
specified.
For example
<!--#echo var = "1CV" -->
inserts the SSI directive named echo, which contains one attribute var whose value is set to 1CV.
DT80 SSI Directives
The DT80 web server supports five SSI directives, which are summarised in the table below. Each directive requires the
indicated attribute to be set. In addition, one or more optional attributes may be included.
Directive
Required Attribute
Function
echo
var
Inserts the current value of the indicated variable
channeltable schedule
Inserts an HTML table containing, for each channel, its schedule, name, most recent
value, units and timestamp – similar to the Channels page
measure channel
Samples the indicated channel (certain channel types only) and inserts the measured
value
reading
channel
Inserts the most recent value of the indicated channel, plus timestamp
include
file
or
Inserts the contents of the indicated text file, specified as a path relative to the
document root (
DOC_ROOT
profile setting
virtual
Inserts the contents of the indicated text file, specified as an absolute path
 Optional Attributes
One optional attribute is supported, which may be applied to any of the above directives in addition to their standard
attribute:
Directive
Attribute
Function
any
cond
Evaluate the directive if and only if the indicated condition is true
The following sections discuss each directive in more detail.