Revision 1.1
WebSwitch™ Users Manual
Appendix D: External Server and Remote Services
Note: The following methods are supported by WebSwitch™; however, Xytronix Research & Design,
Inc. does not provide or support custom third party applications, or external web servers.
Accessing WebSwitch™ with Custom Software or Third Party Applications
WebSwitch™ provides a programming interface that allows applications running on a computer to have
full access to it. Custom applications can send commands to WebSwitch™ for monitoring and control.
They can also be used to provide a custom user interface, provide access to multiple units in a single
screen, and allow for automation, logging, etc.
Using an External Web Server
Rather than accessing WebSwitch™ directly from a computer, an external web server can be used. The
term “external” web server is used here to mean a separate web server (such as Apache or IIS) that is
not the web server built into WebSwitch™. In this scenario, users access custom web pages that reside
on the external web server and the external web server communicates with WebSwitch™. This means
users would not communicate directly with WebSwitch™.
Using an external web server to provide a custom user interface is beneficial because multiple
WebSwitch™ devices (or other ControlByWeb™ products) can be integrated into a single control page
or set of pages so they appear as part of a larger system rather than individual devices. In other words,
the user may not be aware that he/she is using multiple ControlByWeb™ devices, but rather the user
sees a custom control page that shows the entire system. In addition, the use of an external web server
allows programmers to create custom user interfaces that take advantage of the additional resources
typically available on larger web servers, including more memory and various web programming
languages.
There are two approaches that an external server can use to communicate with WebSwitch™ and other
ControlByWeb™ devices, Direct Server Control and Remote Services.
Direct Server Control
The first approach is for the external server to create a TCP connection whenever it needs to access
WebSwitch™. In this case, the external server opens the connection, sends commands and/or reads the
device, and closes the connection.
This method is ideal when the web server and all of WebSwitch™ devices are on the same network
(without routers between them). In this case, the server can communicate with WebSwitch™ directly and
securely since data never has to leave the local network.
When the server and WebSwitch™ are on different networks, routers must be configured to allow
appropriate access. If a public network is used, such as the Internet, security precautions should be
considered.
Remote Services
The second approach is for WebSwitch™ to initiate a connection using the “Remote Services.” The
settings under the
Advanced Network
tab in the setup pages will enable the WebSwitch™ to open a
TCP connection with an external server. Once the connection is open, the external server can send
commands and/or read the device. The external server can leave the connection open (so that it never
closes) or close the connection.
“Remote Services” is ideal for installations where the server and WebSwitch™ are installed on different
networks. This is especially useful when each
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