Appendix E: External Server And Remote Services - Xytronix Research & Design ControlByWeb X317 User Manual

X-317™ Users Manual

Appendix E: External Server and Remote Services

Note: The following methods are supported by the X-317; however, Xytronix Research & Design, Inc.
does not provide or support custom third party applications, or external web servers.
Accessing the X-317 with Custom Software or Third Party Applications
Custom applications can send commands to the X-317 for monitoring and control. The application
interface can be used to provide a custom user interface, access to multiple units in a single screen, and
allow for automation, logging, and other application-specific features.
Using an External Web Server
Rather than accessing the X-317 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 the X-317. In this scenario, users access custom web pages that reside on
the external web server and the external web server communicates with the X-317.
An external web server can integrate multiple ControlByWeb products into a single control page. In other
words, the user may not be aware that he/she is using multiple ControlByWeb™ devices, but rather the
user sees an integrated control page for 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 the X-317 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 the
X-317. 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 the X-317 devices are on the same network (without
routers between them). In this case, the server can communicate with the X-317 devices directly and
securely since data never has to leave the local network.
When the server and the X-317 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 the X-317 to initiate a connection using the "Remote Services." The settings
under the Advanced Network tab in the setup pages will enable the X-317 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 the X-317 are installed on different
networks. This is especially useful when each X-317 is installed on a separate private network. For
example, if the user doesn't control the network connections where the X-317 is installed, "Remote
Services" would initiate a TCP connection over the Internet with the control computer. Since the X-317
initiates the connection, the control computer doesn't have to know the IP address of the X-317. This
means that the X-317 can be installed using DHCP. In addition, no special router configuration is
required. This makes the network installation of the X-317 very simple, and since no incoming ports
Xytronix Research & Design, Inc.
Appendix E: External Server and Remote Services
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