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This TCP server is setup for Stellaris series (LM3S8962) from TI. The TCP/IP stack is lwIP shipped with enet_io app in StellarisWare.

First create and add a C file “tcp_server.c” at “..\StellarisWare\third_party\lwip-1.3.2\apps\tcpserver” folder. Include the prototype in enet_io.c file.

//*****************************************************************************
//
// External Application references.
//
//*****************************************************************************
extern void httpd_init(void);
extern void tcp_server_init(void);

In the main function, call the tcp_server_init() function.
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Here is a very simple example of testing Modbus-TCP with Mango M2M. TCP is a convenient way to transport sensor/control data. The lower layers of TCP insure data reliability. This example only simulates a quick integration of a Modbus-TCP enabled remote terminal unit (RTU) with a SCADA (Mango in this case); it doesn’t give any details of Modbus RTU itself. Modbus data may transported through many other physical media as well, RS485 being the most common. There are several reasons I personally recommend Ethernet over RS485, this post may give you an idea why. This is true not just for Modbus but any communication protocol.

• The first step is to download Modbus Slave utility from here. The is only a 10 minute demo but will serve our purpose. You can search a better option for yourself. Open up the program and click “Connection”, choose “Modbus TCP/IP”.

A few years back I was a part of heated discussed in my company about Smart Grid technology. Basically, our company was asked by a government institution in power sector to do all this. I, along-with one of my colleague, were on our way for a survey for a small demo to be presented before some government officials which could show them the “goodies” of Smart Grid. To demonstrate them how it can control billing, have advanced fault indications, energy harvesting, solve our greatest issue the energy theft and other features.

We spent days selecting the platform for demo as well as for long-term production. We prepared a list of several vendors offering solutions of smart meters. Suddenly the whole project got frozen due to lack of interest from the government agency. All our efforts were in vain. We, as a private company, could not invest resources in something which did not seem fruitful, at least for the time being.

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Often we need to calculate the power ratings of different components in a solar power systems. This may include the battery rating, solar charger rating, number of panels and their ratings. It all depends upon the output load, charging time and resources available. Attached is a very simple excel sheet which helps to calculate these parameters. Just change the parameters on left to see the reflected output calculations on right.

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