Modbus over IP and Web pages on SlimLine Compact

[Gabriel]

I just bought a Slimline Compact CPU (RS485). On presentation web page, I can read about the following features:

-Supported Protocols: Modbus over IP, TCP/IP, UDP
-Applications: Web server for Internet applications.

How can I access those features as there’s no Ethernet port ?

[Sergio Bertana]

All the SlimLine CPU modules and also the Compact, have a mini USB connector (Device mode), by connecting this to the PC USB host port it’s possible to activate the RNDIS driver on the PC. The Remote Network Driver Interface Specification (RNDIS) is a Microsoft proprietary protocol used mostly on top of USB. It provides a virtual Ethernet link to most versions of the Windows operating system.
 
The RNDIS is native in Windows 7 and later. On Windows XP and Vista is prompted for a driver. The necessary drivers can be found in RndisSetup or DriversElsistUsbRNDIS folder in the installation path of the LogicLab program. After installation connecting the SlimLine module to the PC we will find a new network adapter connected to the module. From the control panel Network Interfaces, you can view the network card installed (See screenshot). From the properties must be defined the network address assigned to the new card (By default RNDIS connection on the SlimLine CPU module has IP address 192.168.1.122), so I recommend you to assign the address 192.168.1.10 (See screenshot).
 
In setting the IP be careful to not define a class of network that is in conflict with any existing network card.

[Sergio Bertana]

After setting the IP address the SlimLine CPU module will be accessible by TCP/IP as any modules connected to the network. For example, typing in the address bar of a browser the IP address of the module (Example 192.168.1.122) we can display the configuration web page (See screenshot).

Similarly we can access to it from LogicLab with Modbus TCP connection on port 502, from Telnet on port 23 and FTP on port 21. By accessing in FTP in Windows Explorer (ftp://admin:admin@192.168.1.122 in the address bar) we can see the file system of the CPU module (See screenshot).

[Sergio Bertana]

The most important feature of the integrated web server in SlimLine is the ability to handle dynamic pages. A dynamic web page is a page whose content, in whole or in part, is generated by the server on demand, and therefore can be different each time it is requested, thus allowing interactivity with the user.

Hence it will be possible to create a page that lists and allows to change the value of PLC variables. I enclose an abstract from the manual IEC61131-3 SlimLine system that covers the subject (Abstract download).

[Autore]

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