Ethernet is a physical and data link layer technology for local area networks (LANs). Ethernet was invented by engineer Robert Metcalfe.
When first widely deployed in the 1980s, Ethernet supported a maximum theoretical data rate of 10 megabits per second (Mbps). Later, so-called "Fast Ethernet" standards increased this maximum data rate to 100 Mbps. Gigabit Ethernet technology further extends peak performance up to 1000 Mbps, and 10 Gigabit Ethernet technology also exists.
Higher level network protocols like Internet Protocol (IP) use Ethernet as their transmission medium. Data travels over Ethernet inside protocol units called frames. The run length of individual Ethernet cable is limited to roughly 100 meters, but Ethernet networks can be easily extended to link entire schools or office buildings using network bridge devices.
#include <windows.h> #include <stdio.h> #include <winsock2.h> #pragma comment(lib, "Ws2.lib") /// Set IP address and port number according to server IP address and port number #define SERVER_IP_ADDRESS "10.18.1.105" #define PORT_NUMBER 23 #define BUFFER_SIZE 255 int wmain() { DWORD choice = 0; BOOL loopMenu = TRUE; WSADATA ws; ///< Structure to contain information about the Windows Socket implementation SOCKET commSocket; int retVal = 0; char sendBuffer[BUFFER_SIZE] = {0}; char recvBuffer[BUFFER_SIZE] = {0}; struct sockaddr_in serverinfo; retVal = WSAStartup(0x0101, &ws); ///< Initialize ws2.dll (library used for socket programming) if (retVal != 0) ///< If WSAStartup failed to initialize { printf("WSAStartup failed with error: %d\n", WSAGetLastError()); exit(1); } commSocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); ///< Socket creation if (commSocket == INVALID_SOCKET) { printf("\nSocket creation failed with error code : %d", WSAGetLastError()); WSACleanup(); exit(1); } /// Socket binding serverinfo.sin_family = AF_INET; ///< TCP/UDP socket serverinfo.sin_addr.s_addr = inet_addr(SERVER_IP_ADDRESS); ///< IP Address of Server serverinfo.sin_port = htons(PORT_NUMBER); ///< Port number used for communication retVal = connect(commSocket, (LPSOCKADDR)&serverinfo, sizeof(struct sockaddr)); ///< Connect to Server if (retVal == SOCKET_ERROR) { printf("\nCould not connect to Server with error code : %d", WSAGetLastError()); WSACleanup(); return FALSE; } printf("Demo program to send and receive data over LAN, Toradex Module as client\n"); while (loopMenu == TRUE) { printf("\n1. Send\n2. Receive\n3. Exit\n"); scanf_s("%d", &choice); switch(choice) { case 1: printf("\nSend = "); scanf_s("%s", sendBuffer); retVal = send(commSocket, sendBuffer, strlen(sendBuffer), 0); if (retVal == SOCKET_ERROR) { printf("\nCould not send message to Server with error code : %d", WSAGetLastError()); } break; case 2: printf("\nEntering Listen Mode \n"); retVal = recv(commSocket, recvBuffer, BUFFER_SIZE, 0); ///< Receive from server if (retVal == SOCKET_ERROR) { printf("\nCould not receive from Server with error code : %d", WSAGetLastError()); } else { printf("\nMessage received from server : %s", recvBuffer); memset(&recvBuffer[0], 0, sizeof(recvBuffer)); } break; case 3: loopMenu = FALSE; break; default: printf("\nInvalid Choice"); break; } } closesocket(commSocket); WSACleanup(); ///< Releasing ws2.dll return TRUE; }
You can download demo source code from here.
Make sure to run the application on module first before connecting to TCP server from client (e.g Hercules on host computer).
#include <windows.h> #include <stdio.h> #include <winsock2.h> #pragma comment(lib, "Ws2.lib") /// Set device IP address and port number #define DEVICE_IP_ADDRESS "10.18.0.133" #define PORT_NUMBER 23 #define BUFFER_SIZE 255 int wmain() { WSADATA ws; ///< Structure to contain information about the Windows Socket implementation DWORD retVal = 0; DWORD choice = 0; BOOL loopCounter = TRUE; SOCKET listeningSocket; SOCKET commsocket; CHAR sendbuffer[BUFFER_SIZE] = {0}; CHAR recvbuffer[BUFFER_SIZE] = {0}; struct sockaddr_in serverinfo; printf("Demo Program to send and receive data over LAN, Toradex Module as server\n"); retVal = WSAStartup(0x0101, &ws); ///< Initiating use of ws2.dll if (retVal != 0) ///< If WSAStartup failed to initialize { printf("WSAStartup failed with error code: %d\n", retVal); WSACleanup(); exit(1); } listeningSocket = socket(AF_INET,SOCK_STREAM,IPPROTO_TCP); ///< Socket creation if (listeningSocket == INVALID_SOCKET) { printf("\nSocket creation failed with error code : %d", WSAGetLastError()); WSACleanup(); exit(1); } /// Socket binding serverinfo.sin_family = AF_INET; ///< TCP/UDP socket serverinfo.sin_addr.s_addr = inet_addr(DEVICE_IP_ADDRESS); ///< IP Address of Toradex module serverinfo.sin_port = htons(PORT_NUMBER); ///< Port number: used for communication retVal = bind(listeningSocket, (SOCKADDR *)&serverinfo, sizeof(struct sockaddr)); if (retVal == SOCKET_ERROR) { printf("\nSocket binding failed with error code : %d", WSAGetLastError()); WSACleanup(); exit(1); } retVal = listen(listeningSocket, 1); ///< Listen for 1 socket only if (retVal == SOCKET_ERROR) { printf("\nSocket listening failed with error code : %d", WSAGetLastError()); WSACleanup(); exit(1); } printf("\nWaiting for client to respond...."); commsocket = accept(listeningSocket, NULL, NULL); ///< Waiting for request from client if (commsocket == INVALID_SOCKET) { printf("\nConnection failed with error code : %d", WSAGetLastError()); WSACleanup(); exit(1); } while (loopCounter == TRUE) { printf("\n1. Send\n2. Receive\n3. Exit\n"); scanf_s("%d", &choice); switch(choice) { case 1: printf("Send Message = "); scanf_s("%s", sendbuffer); retVal = send(commsocket, sendbuffer, strlen(sendbuffer), 0); ///< Sending to client if (retVal == SOCKET_ERROR) { printf("\nFailed to receive from client with error code : %d", WSAGetLastError()); } break; case 2: printf("\nListening socket..."); retVal = recv(commsocket, recvbuffer, BUFFER_SIZE, 0); ///< Receiving from client recvbuffer[retVal] = 0; if (retVal == SOCKET_ERROR) { printf("\nFailed to receive from client with error code : %d", WSAGetLastError()); } else { printf("\nMessage from Client : %s", recvbuffer); } break; case 3: loopCounter = FALSE; break; default: printf("Invalid choice \n"); break; } } closesocket(commsocket); ///< Closing communication socket closesocket(listeningSocket); ///< Closing listening socket WSACleanup(); ///< Releasing ws2.dll return TRUE; }
You can download demo source code from here.
#include <windows.h> #include <stdio.h> #include <winsock2.h> #pragma comment(lib, "Ws2.lib") /// Set IP address and port number according to server IP address and port number #define SERVER_IP_ADDRESS "10.18.0.100" #define PORT_NUMBER 23 #define BUFFER_SIZE 255 #define ASCII_CTRLZ "26" ///< ASCII of CTRT+Z or EOF to exit from code. HANDLE hCom; ///< Handle for thread SOCKET commSocket; ///< Structure to contain SOCKET configuration HANDLE myEvent; ///< Handle to Event declared DWORD retVal; CHAR sendBuffer[BUFFER_SIZE] = {0}; /// Thread for Sending data DWORD SendThreadProc(LPVOID hCom) { while(1) { WaitForSingleObject(myEvent, INFINITE); retVal = send(commSocket, sendBuffer, strlen(sendBuffer), 0); if (retVal == SOCKET_ERROR) { printf("\nCould not send message to Server with error code : %d", WSAGetLastError()); CloseHandle(myEvent); return 0; } sendBuffer[0] = '\0'; } } /// Thread for receiving data DWORD ReceiveThreadProc(LPVOID hCom) { char recvBuffer[BUFFER_SIZE] = {0}; while(1) { retVal = recv(commSocket, recvBuffer, BUFFER_SIZE, 0); ///< Receive from server if (retVal == SOCKET_ERROR) { printf("\nCould not receive from Server with error code : %d", WSAGetLastError()); return 0; //break; } else if(retVal == 0) { break; } else { printf("Data Received: %s\n", recvBuffer); //break; } } } int wmain() { DWORD choice = 0; DWORD oldMode = 0; BOOL loopMenu = TRUE; WSADATA ws; ///< Structure to contain information about the Windows Socket implementation struct sockaddr_in serverinfo; myEvent = CreateEventW(NULL, FALSE, FALSE, NULL); ///< Creating an Event to enter data on console retVal = WSAStartup(0x0101, &ws); ///< Initialize ws2.dll (library used for socket programming) if (retVal != 0) ///< If WSAStartup failed to initialize { printf("WSAStartup failed with error: %d\n", WSAGetLastError()); exit(1); } commSocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); ///< Socket creation if (commSocket == INVALID_SOCKET) { printf("\nSocket creation failed with error code : %d", WSAGetLastError()); WSACleanup(); exit(1); } /// Socket binding serverinfo.sin_family = AF_INET; ///< TCP/UDP socket serverinfo.sin_addr.s_addr = inet_addr(SERVER_IP_ADDRESS); ///< IP Address of Server serverinfo.sin_port = htons(PORT_NUMBER); ///< Port number used for communication retVal = connect(commSocket, (LPSOCKADDR)&serverinfo, sizeof(struct sockaddr)); ///< Connect to Server if (retVal == SOCKET_ERROR) { printf("\nCould not connect to Server with error code : %d", WSAGetLastError()); WSACleanup(); return FALSE; } printf("Demo program to send and receive data over LAN using Multi Threading,\nToradex Module as client" "\n*****PRESS CTRL + Z and ENTER to EXIT*****\n"); CreateThread(NULL, 0, SendThreadProc, hCom, 0, NULL); ///< Thread declaration to Send Data CreateThread(NULL, 0, ReceiveThreadProc, hCom, 0, NULL); ///< Thread declaration to Receive Data while(!feof(stdin)) { scanf_s("%s", sendBuffer); if(sendBuffer == ASCII_CTRLZ) { break; } else { if(!SetEvent(myEvent)) ///< Setting Event Flag { printf("Event not Set: %d", GetLastError()); break; } } } closesocket(commSocket); WSACleanup(); ///< Releasing ws2.dll return TRUE; }
You can download demo source code from here.
