w5500 modbustcp例程

以下是W5500模块实现Modbus/TCP协议的例程：

#include <stdio.h>
#include <string.h>
#include "stm32f10x.h"
#include "w5500.h"
#include "socket.h"

#define ETH_MAX_BUF_SIZE 2048

uint8_t ethBuf0[ETH_MAX_BUF_SIZE];
uint8_t ethBuf1[ETH_MAX_BUF_SIZE];

uint8_t macAddr[6] = {0x00, 0x08, 0xdc, 0xab, 0xcd, 0xef};
uint8_t ipAddr[4] = {192, 168, 1, 100};
uint8_t gwAddr[4] = {192, 168, 1, 1};
uint8_t snMask[4] = {255, 255, 255, 0};

uint16_t modbusTcpPort = 502;

uint8_t modbusTcpBuf[ETH_MAX_BUF_SIZE];

void initW5500(void)
{
    uint8_t tmp[2];

    W5500_Init();

    W5500_SetMACAddress(macAddr);
    W5500_SetIPAddress(ipAddr);
    W5500_SetGatewayAddress(gwAddr);
    W5500_SetSubnetMask(snMask);

    W5500_GetGatewayAddress(tmp);
    printf("Gateway Address: %d.%d.%d.%d\n", tmp[0], tmp[1], tmp[2], tmp[3]);

    W5500_GetSubnetMask(tmp);
    printf("Subnet Mask: %d.%d.%d.%d\n", tmp[0], tmp[1], tmp[2], tmp[3]);
}

void modbusTcpServer(void)
{
    uint8_t socket0, socket1;
    uint16_t len;
    uint16_t i;

    socket0 = socket(0, Sn_MR_TCP, modbusTcpPort, 0);
    listen(socket0);

    while (1)
    {
        if (getSn_SR(socket0) == SOCK_ESTABLISHED)
        {
            len = getSn_RX_RSR(socket0);
            if (len > 0)
            {
                if (len > ETH_MAX_BUF_SIZE)
                {
                    len = ETH_MAX_BUF_SIZE;
                }
                recv(socket0, ethBuf0, len);
                memcpy(modbusTcpBuf, ethBuf0, len);

                // Modbus/TCP protocol processing
                // ...

                send(socket0, modbusTcpBuf, len);
            }
        }
    }
}

int main(void)
{
    initW5500();

    modbusTcpServer();

    return 0;
}