Download Webdyngate Modbus User`s Manual

Webdyngate Modbus Version 1.10 User’s Manual
For example, the administrator can access the Web server of the gateway from a
browser and the following URL http://192.168.2.12.
A remote connection of the gateway to an IAP can be summarized as comprising the
following actions:
The gateway and the modem initiate a telephone call to the IAP.
The IAP off-hooks.
The IAP authenticates the gateway’s id information.
The IAP attributes an official IP address (address accessible to any device
connected on the Internet).
The gateway connects to the SMTP server and sends its e-mail.
The gateway on-hooks and returns to the WAIT mode.
If an error is detected (for example the line is busy), all the preceding actions are
reiterated three times.
5.6.2 IPCallBack WAIT mode
When they use Internet technologies, (TCP/IP and other Web-based tools) users of
Modbus Webdyngate gateways have access to new perspectives.
The basic idea is that through an Internet connection, one can control any device
using standard tools and protocols.
Using this architecture the aim is to be able to control devices remotely using
standard and sustainable tools (Internet browser, messaging) and protocols (TCP/IP,
HTTP, FTP, SMTP, SNMP).
One of the major advantages of the Internet is to be able to use the world network as
an infrastructure. The interest of using the Internet as a communication medium is
basically economical. Thanks to the Internet, the cost of communication is limited to
the cost of a local call.
To achieve this objective, the Webdyngate gateway must have an official IP address
and the link between the gateway and the Internet must be permanent.
This type of architecture can be set up over an ADSL link, over a leased line or over
cable.
However, it is not possible to keep a permanent link open on the STN at low cost.
In the previous hypothesis (WAIT incoming call mode) the connection was set up on
a temporary point-to-point link (thus private) with the cost of communication
depending on the distance between the two devices.
To use an Internet link and thus pay the local rates, the only way is to use an IAP.
If the Webdyngate is connected to its IAP via an STN modem, the problem is as
follows:
Page 30
Copyright (C) Webdyn 2003
Reproduction prohibited without written permission from Webdyn