环保公司网站建设,wordpress+时钟插件,网站建设公司类型,百度上海分公司RT-Thread中已经有不少Modbus相关在线软件包#xff0c;但总体应用起来还是相对复杂#xff0c;所以在RT-Thread基于AT32单片机的485应用开发#xff08;二#xff09;的基础上实现了一个极简Modbus从机#xff0c;支持Modbus功能码01#xff0c;02#xff0c;03#x…RT-Thread中已经有不少Modbus相关在线软件包但总体应用起来还是相对复杂所以在RT-Thread基于AT32单片机的485应用开发二的基础上实现了一个极简Modbus从机支持Modbus功能码0102030405061516。
在具体项目中只要实现下面几个函数就可以直接用了不过需要注意多线程访问变量加锁问题。
rt_weak rt_err_t mb_write_coil_cb(unsigned short addr, unsigned short val){return RT_EOK;}
rt_weak rt_err_t mb_write_holding_cb(unsigned short addr, unsigned short val){return RT_EOK;}
rt_weak unsigned short mb_read_coil_cb(unsigned short addr){return 0;}
rt_weak unsigned short mb_read_di_cb(unsigned short addr){return 0;}
rt_weak unsigned short mb_read_holding_cb(unsigned short addr){return 0;}
rt_weak unsigned short mb_read_input_cb(unsigned short addr){return 0;}只需要在项目中增加两个文件就可以实现基于RS485的ModbusRTU设备。
1. mb_core.c
#include rtthread.hstatic unsigned int MB_COIL_NUM 16;
static unsigned int MB_DI_NUM 16;
static unsigned int MB_HOLDING_NUM 32;
static unsigned int MB_INPUT_NUM 32;static unsigned char DEV_ADDR 1;rt_weak rt_err_t mb_write_coil_cb(unsigned short addr, unsigned short val){return RT_EOK;}
rt_weak rt_err_t mb_write_holding_cb(unsigned short addr, unsigned short val){return RT_EOK;}
rt_weak unsigned short mb_read_coil_cb(unsigned short addr){return 0;}
rt_weak unsigned short mb_read_di_cb(unsigned short addr){return 0;}
rt_weak unsigned short mb_read_holding_cb(unsigned short addr){return 0;}
rt_weak unsigned short mb_read_input_cb(unsigned short addr){return 0;}/* 高位字节的 CRC 值 */
static unsigned char auchCRCHi[] { 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1,0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1,0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0,0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1,0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40,0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1,0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40,0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1,0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1,0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40 };
/* 低位字节的 CRC 值 */
static char auchCRCLo[] { 0x00, 0xC0, 0xC1, 0x01, 0xC3, 0x03, 0x02, 0xC2, 0xC6, 0x06, 0x07, 0xC7, 0x05, 0xC5, 0xC4,0x04, 0xCC, 0x0C, 0x0D, 0xCD, 0x0F, 0xCF, 0xCE, 0x0E, 0x0A, 0xCA, 0xCB, 0x0B, 0xC9, 0x09, 0x08, 0xC8, 0xD8,0x18, 0x19, 0xD9, 0x1B, 0xDB, 0xDA, 0x1A, 0x1E, 0xDE, 0xDF, 0x1F, 0xDD, 0x1D, 0x1C, 0xDC, 0x14, 0xD4, 0xD5,0x15, 0xD7, 0x17, 0x16, 0xD6, 0xD2, 0x12, 0x13, 0xD3, 0x11, 0xD1, 0xD0, 0x10, 0xF0, 0x30, 0x31, 0xF1, 0x33,0xF3, 0xF2, 0x32, 0x36, 0xF6, 0xF7, 0x37, 0xF5, 0x35, 0x34, 0xF4, 0x3C, 0xFC, 0xFD, 0x3D, 0xFF, 0x3F, 0x3E,0xFE, 0xFA, 0x3A, 0x3B, 0xFB, 0x39, 0xF9, 0xF8, 0x38, 0x28, 0xE8, 0xE9, 0x29, 0xEB, 0x2B, 0x2A, 0xEA, 0xEE,0x2E, 0x2F, 0xEF, 0x2D, 0xED, 0xEC, 0x2C, 0xE4, 0x24, 0x25, 0xE5, 0x27, 0xE7, 0xE6, 0x26, 0x22, 0xE2, 0xE3,0x23, 0xE1, 0x21, 0x20, 0xE0, 0xA0, 0x60, 0x61, 0xA1, 0x63, 0xA3, 0xA2, 0x62, 0x66, 0xA6, 0xA7, 0x67, 0xA5,0x65, 0x64, 0xA4, 0x6C, 0xAC, 0xAD, 0x6D, 0xAF, 0x6F, 0x6E, 0xAE, 0xAA, 0x6A, 0x6B, 0xAB, 0x69, 0xA9, 0xA8,0x68, 0x78, 0xB8, 0xB9, 0x79, 0xBB, 0x7B, 0x7A, 0xBA, 0xBE, 0x7E, 0x7F, 0xBF, 0x7D, 0xBD, 0xBC, 0x7C, 0xB4,0x74, 0x75, 0xB5, 0x77, 0xB7, 0xB6, 0x76, 0x72, 0xB2, 0xB3, 0x73, 0xB1, 0x71, 0x70, 0xB0, 0x50, 0x90, 0x91,0x51, 0x93, 0x53, 0x52, 0x92, 0x96, 0x56, 0x57, 0x97, 0x55, 0x95, 0x94, 0x54, 0x9C, 0x5C, 0x5D, 0x9D, 0x5F,0x9F, 0x9E, 0x5E, 0x5A, 0x9A, 0x9B, 0x5B, 0x99, 0x59, 0x58, 0x98, 0x88, 0x48, 0x49, 0x89, 0x4B, 0x8B, 0x8A,0x4A, 0x4E, 0x8E, 0x8F, 0x4F, 0x8D, 0x4D, 0x4C, 0x8C, 0x44, 0x84, 0x85, 0x45, 0x87, 0x47, 0x46, 0x86, 0x82,0x42, 0x43, 0x83, 0x41, 0x81, 0x80, 0x40 };static unsigned short CRC16_ModBus(unsigned char *puchMsg, unsigned char usDataLen)
{unsigned char uchCRCHi 0xFF; /* CRC 的高字节初始化 */unsigned char uchCRCLo 0xFF; /* CRC 的低字节初始化 */unsigned char uIndex; /* CRC 查询表索引 */while (usDataLen--) /* 完成整个报文缓冲区 */{uIndex uchCRCLo ^ *puchMsg; /* 计算 CRC */uchCRCLo uchCRCHi ^ auchCRCHi[uIndex];uchCRCHi auchCRCLo[uIndex];}return (uchCRCHi 8 | uchCRCLo);
}static int frame_available(unsigned char *buf, int len)
{int data_len 0, num;if (len 5)return 0;if (buf[1] 1 || buf[1] 2 || buf[1] 3 || buf[1] 4 || buf[1] 5 || buf[1] 6){data_len 4;}else if (buf[1] 15){num ((buf[4] 8) | buf[5]);data_len 4 1 (num 7) / 8;}else if (buf[1] 16){num ((buf[4] 8) | buf[5]);data_len 4 1 num * 2;}else if (buf[1] 0x80){data_len 1;}else{return -1;}if (len data_len 4)return 0;unsigned short crc CRC16_ModBus(buf, 2 data_len);if (crc (buf[2 data_len] | ((buf[2 data_len 1]) 8))){return 1;}return -1;
}void mb_slave_init(unsigned char slave_addr, int coil_num, int di_num, int holding_num, int input_num)
{MB_COIL_NUM coil_num;MB_DI_NUM di_num;MB_HOLDING_NUM holding_num;MB_INPUT_NUM input_num;DEV_ADDR slave_addr;
}int mb_slave_process(unsigned char *rx_buf, int rx_len, unsigned char *tx_buf)
{unsigned char error_code 0;unsigned short num, addr, val, ind 0, crc16, bytes;int ret frame_available(rx_buf, rx_len);//frame errorif (ret 0)return ret;//valid addrif (rx_buf[0] ! DEV_ADDR)return 0;//process rtu cmdswitch (rx_buf[1]){case 1: //read coilcase 2: //read diaddr (rx_buf[2] 8) | rx_buf[3];num (rx_buf[4] 8) | rx_buf[5];if (num 1 || num 0x7d0){error_code 3;break;}if (addr num (rx_buf[1] 1 ? MB_COIL_NUM : MB_DI_NUM)){error_code 2;break;}tx_buf[ind] DEV_ADDR;tx_buf[ind] rx_buf[1];bytes (num 7) / 8;tx_buf[ind] bytes;for (int i 0; i bytes; i){tx_buf[ind i] 0;}for (int i 0; i num; i){if (rx_buf[1] 1)//coil{val mb_read_coil_cb(i addr);if (val)tx_buf[ind i / 8] | 1 (i % 8);}else//di{val mb_read_di_cb(i addr);if (val)tx_buf[ind i / 8] | 1 (i % 8);}}ind bytes;crc16 CRC16_ModBus(tx_buf, ind);tx_buf[ind] crc16;tx_buf[ind] crc16 8;break;case 3: //read holdingcase 4: //read inputaddr (rx_buf[2] 8) | rx_buf[3];num (rx_buf[4] 8) | rx_buf[5];if (num 1 || num 125){error_code 3;break;}if (addr num (rx_buf[1] 3 ? MB_HOLDING_NUM : MB_INPUT_NUM)){error_code 2;break;}tx_buf[ind] DEV_ADDR;tx_buf[ind] rx_buf[1];tx_buf[ind] num * 2;for (int i 0; i num; i){if (rx_buf[1] 3)//holding{val mb_read_holding_cb(i addr);tx_buf[ind] val 8;tx_buf[ind] val;}else//input{val mb_read_input_cb(i addr);tx_buf[ind] val 8;tx_buf[ind] val;}}crc16 CRC16_ModBus(tx_buf, ind);tx_buf[ind] crc16;tx_buf[ind] crc16 8;break;case 5: //write single coilcase 6: //write single regaddr (rx_buf[2] 8) | rx_buf[3];val (rx_buf[4] 8) | rx_buf[5];if (val ! 0x0 val ! 0xff00 rx_buf[1] 5){error_code 3;break;}if (addr (rx_buf[1] 5 ? MB_COIL_NUM : MB_HOLDING_NUM)){error_code 2;break;}for (int i 0; i 8; i){tx_buf[i] rx_buf[i];}if (rx_buf[1] 5){if (0 ! mb_write_coil_cb(addr, val))error_code 4;}else{if (0 ! mb_write_holding_cb(addr, val))error_code 4;}ind 8;break;case 15: //wrtie multi coilsaddr (rx_buf[2] 8) | rx_buf[3];num (rx_buf[4] 8) | rx_buf[5];if (num 1 || num 0x7b || rx_buf[6] ! (num 7) / 8){error_code 3;break;}if (addr num MB_COIL_NUM){error_code 2;break;}for (ind 0; ind 6; ind){tx_buf[ind] rx_buf[ind];}for (int i 0; i num; i){val rx_buf[7 i / 8] (1 (i % 8));if (mb_write_coil_cb(addr i, val) ! 0)error_code 4;}crc16 CRC16_ModBus(tx_buf, ind);tx_buf[ind] crc16;tx_buf[ind] crc16 8;break;case 16: //write multi regsaddr (rx_buf[2] 8) | rx_buf[3];num (rx_buf[4] 8) | rx_buf[5];if (num 1 || num 0x7b || rx_buf[6] ! num * 2){error_code 3;break;}if (addr num MB_HOLDING_NUM){error_code 2;break;}for (ind 0; ind 6; ind){tx_buf[ind] rx_buf[ind];}for (int i 0; i num; i){val (rx_buf[7 2 * i] 8) | rx_buf[7 2 * i 1];if (0 ! mb_write_holding_cb(addr i, val))error_code 4;}crc16 CRC16_ModBus(tx_buf, ind);tx_buf[ind] crc16;tx_buf[ind] crc16 8;break;default:if (rx_buf[1] 0x80)return 0;elseerror_code 1;break;}if (error_code ! 0){ind 0;tx_buf[ind] DEV_ADDR;tx_buf[ind] rx_buf[1] | 0x80;tx_buf[ind] error_code;crc16 CRC16_ModBus(tx_buf, ind);tx_buf[ind] crc16;tx_buf[ind] crc16 8;}return ind;
}2. rs_485_test.c
#include rtthread.h
#include rtdevice.h/* 串口设备句柄 */
static rt_device_t serial;/* 485控制引脚 */
static rt_base_t rs485_ctrl_pin -1;/* timeout receive */
static int serial_read_frame(rt_device_t dev, uint8_t *buf, int max_len, uint32_t idle_ms, int timeout_ms)
{int rx_len 0, rc;uint32_t idle_time, timeout_time, cur_tick, last_tick;timeout_time rt_tick_from_millisecond(timeout_ms);idle_time rt_tick_from_millisecond(idle_ms);cur_tick rt_tick_get();while ((rt_tick_get() - last_tick idle_time rx_len max_len) || rx_len 0){rc rt_device_read(dev, rx_len, buf, max_len - rx_len);if (rc 0){rx_len rc;last_tick rt_tick_get();}else{rt_thread_mdelay(1);}if (rt_tick_get() - cur_tick timeout_time rx_len 0)break;}return rx_len;
}
/* transmit with auto 485 pin ctrl */
static void serial_write_frame_rs485(rt_device_t dev, uint8_t *buf, int len, int bitrate, int ctrl_pin)
{int ms len * 10 * 1000 / bitrate 2;rt_pin_write(rs485_ctrl_pin, 1);rt_hw_us_delay(10);rt_device_write(dev, 0, buf, len);rt_thread_mdelay(ms);rt_pin_write(rs485_ctrl_pin, 0);
}static void serial_thread_entry(void *parameter)
{extern void mb_slave_init(unsigned char slave_addr, int coil_num, int di_num, int holding_num, int input_num);extern int mb_slave_process(unsigned char *rx_buf, int rx_len, unsigned char *tx_buf);rt_uint32_t rx_len, tx_len;static unsigned char rx_buf[260];static unsigned char tx_buf[260];mb_slave_init(1,16,16,32,32);while (1){rx_len serial_read_frame(serial, rx_buf, 260, 10, 1000);if (rx_len 0)continue;tx_len mb_slave_process(rx_buf, rx_len, tx_buf);if(tx_len0)serial_write_frame_rs485(serial, rx_buf, rx_len, 115200, rs485_ctrl_pin);/* 打印数据 */rx_buf[rx_len] \0;rt_kprintf(rx_len %d\n, rx_len);}
}static int uart_485_sample(int argc, char *argv[])
{rt_err_t ret RT_EOK;char uart_name[RT_NAME_MAX] uart4;if (argc 2){rt_strncpy(uart_name, argv[1], RT_NAME_MAX);}rt_kprintf(uart_name %s\n, uart_name);if (rt_strcmp(uart_name,uart3) 0){rs485_ctrl_pin rt_pin_get(PE.15);rt_pin_mode(rs485_ctrl_pin, PIN_MODE_OUTPUT);rt_pin_write(rs485_ctrl_pin, 0);}else if (rt_strcmp(uart_name,uart4) 0){rs485_ctrl_pin rt_pin_get(PA.15);rt_pin_mode(rs485_ctrl_pin, PIN_MODE_OUTPUT);rt_pin_write(rs485_ctrl_pin, 0);}else{return RT_ERROR;}/* 查找串口设备 */serial rt_device_find(uart_name);if (!serial){rt_kprintf(find %s failed!\n, uart_name);return RT_ERROR;}/* 以 DMA 接收及轮询发送方式打开串口设备 */rt_device_open(serial, RT_DEVICE_FLAG_RX_NON_BLOCKING | RT_DEVICE_FLAG_TX_NON_BLOCKING);/* 创建 serial 线程 */rt_thread_t thread rt_thread_create(serial, serial_thread_entry, RT_NULL, 1024, 25, 10);/* 创建成功则启动线程 */if (thread ! RT_NULL){rt_thread_startup(thread);}else{ret RT_ERROR;}return ret;
}
/* 导出到 msh 命令列表中 */
MSH_CMD_EXPORT(uart_485_sample, uart device rs485 sample);经实验测试总体性能还错。对于简单Modbus设备基本可以满足要求。
