10 FreeModbus读多个寄存器数据，在大地址下报MB_MRE_EXE_FUN

发布于 2022-01-18 00:28:44 浏览：1732 订阅该版

[tocm]

## 问题描述
使用freemodbus主机协议栈，调用eMBMasterReqReadHoldingRegister()，寄存器地址设置为0000H时可以正常读取，但设置为0606H后，产生“MB_MRE_EXE_FUN”功能码错误的异常。

```c
/*
 * Copyright (c) 2006-2021, RT-Thread Development Team
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Change Logs:
 * Date           Author       Notes
 * 2022-01-10     zf_19       the first version
 */

#include <rtthread.h>

#include "mb.h"
#include "mb_m.h"
#include "user_mb_app.h"

#ifdef PKG_MODBUS_MASTER_SAMPLE
#define SLAVE_ADDR      MB_SAMPLE_TEST_SLAVE_ADDR
#define PORT_NUM        MB_MASTER_USING_PORT_NUM
#define PORT_BAUDRATE   MB_MASTER_USING_PORT_BAUDRATE
#else
#define SLAVE_ADDR      0x01
#define PORT_NUM        5
#define PORT_BAUDRATE   9600
#endif

#define PORT_PARITY     MB_PAR_NONE  //无校验位

#define MB_POLL_THREAD_PRIORITY  10
#define MB_SEND_THREAD_PRIORITY  RT_THREAD_PRIORITY_MAX - 1

#define MB_SEND_REG_START  3
#define MB_SEND_REG_NUM    3
#define MB_POLL_CYCLE_MS   500      //轮询间隔时间  5个传感器一轮走完需要500ms

/*RS485_RE  PI4  对应PI4引脚应填写：132 (I-A=8)*16+4=132   串口使用U5*/

/*各传感器地址配置*/
#define Displacement_sensor01_SLAVE_ADDR      0x01
#define Displacement_sensor02_SLAVE_ADDR      0x02
#define Displacement_sensor03_SLAVE_ADDR      0x03
#define Displacement_sensor04_SLAVE_ADDR      0x04
#define Angle_sensor01_SLAVE_ADDR             0X05

/*寄存器地址配置*/
#define MB_READ_REG_00                        0x00 //读当前测量值
#define MB_READ_REG_01                        0x01 //仪表类比及当前信息
#define MB_READ_REG_02                        0x02 //仪表编号低四位

#define MB_READ_REG_LL_0606                   0X0606//L600拉力传感器信息保存寄存器
#define MB_READ_REG_LL_9C04                   0X9C04//L600拉力传感器信息保存寄存器
/*寄存器数量---modbus 读数据的长度*/
#define MB_READ_REG_NUM_01                       1
#define MB_READ_REG_NUM_02                       2
#define MB_READ_REG_NUM_03                       3
#define MB_READ_REG_NUM_04                       4

static int is_got = 0;

extern USHORT   usMRegHoldBuf[MB_MASTER_TOTAL_SLAVE_NUM][M_REG_HOLDING_NREGS];// modbus master 用全局二维数组来记录多个从机的数据

/*进行touchgfx数据更新、电压测量板显示数据格式为signed short -32768~32767*/
int16_t value_FY_DCD_10;
int16_t value_HX_DCD_10;
int16_t value_ZHG_DCD_10;
int16_t value_YHG_DCD_10;

int16_t value_PULL_DLM_20;

/*上传到model俯仰DCD-10传感器信息*/
static int gfxget_FY_DCD_10(void)
{

return value_FY_DCD_10;
}

/*上传到model航向DCD-10传感器信息*/
static int gfxget_HX_DCD_10(void)
{
    return value_HX_DCD_10;
}

/*上传到model左横滚DCD-10传感器信息*/
static int gfxget_ZHG_DCD_10(void)
{
    return value_ZHG_DCD_10;
}

/*上传到model右横滚DCD-10传感器信息*/
static int gfxget_YHG_DCD_10(void)
{
    return value_YHG_DCD_10;
}

static int gfxget_PULL_DLM_20(void)
{
    return value_PULL_DLM_20;
}

/*读取各传感器信息线程*/
static void send_thread_entry(void *parameter)
{
    eMBMasterReqErrCode error_code = MB_MRE_NO_ERR;
    rt_uint16_t error_count = 0;

while (1)
    {
        /* Test Modbus Master */
/*      data[0] = (USHORT)(rt_tick_get() / 10);
        data[1] = (USHORT)(rt_tick_get() % 10);*/
        /*接收标志位置零*/
        is_got = 0;
/*
        //往从机多个保持寄存器写入数据
        error_code = eMBMasterReqWriteMultipleHoldingRegister(SLAVE_ADDR,           //salve address
                                                              MB_SEND_REG_START,    //register start address
                                                              MB_SEND_REG_NUM,      //register total number
                                                              data,                 //data to be written
                                                              RT_WAITING_FOREVER);  //timeout
*/

/*        //读位移传感器1多个保持寄存器数据
        error_code = eMBMasterReqReadHoldingRegister(Displacement_sensor01_SLAVE_ADDR,
                                                     MB_READ_REG_00,
                                                     MB_READ_REG_NUM_01,
                                                     500);

//读位移传感器2,000H多个保持寄存器数据
        error_code = eMBMasterReqReadHoldingRegister(Displacement_sensor02_SLAVE_ADDR,
                                                     MB_READ_REG_00,                    //0000H寄存器
                                                     MB_READ_REG_NUM_01,               //读取数据数量
                                                            500);

//读位移传感器3,0000H多个保持寄存器数据
        error_code = eMBMasterReqReadHoldingRegister(Displacement_sensor03_SLAVE_ADDR,
                                                     MB_READ_REG_00,                    //0000H寄存器
                                                     MB_READ_REG_NUM_01,                //读取数据数量
                                                            500);

//读位移传感器4,0000H开始5个保持寄存器数据
        error_code = eMBMasterReqReadHoldingRegister(Displacement_sensor04_SLAVE_ADDR,
                                                     MB_READ_REG_00,                    //0000H寄存器
                                                     MB_READ_REG_NUM_01,                //读取数据数量
                                                            500);*/
        //读角度传感器5,0000H开始2个保持寄存器数据
        error_code = eMBMasterReqReadHoldingRegister(Angle_sensor01_SLAVE_ADDR,         //角度传感器地址
                                                     MB_READ_REG_LL_0606,                    //0606H寄存器
                                                     MB_READ_REG_NUM_02,                //读取数据数量
                                                     500);

/*        //打印节点1俯仰传感器 保持寄存器的数据
        value_FY_DCD_10 = (int16_t)usMRegHoldBuf[0][0];
        rt_kprintf("sensor1_detect: %d \t\r\n", (int16_t)usMRegHoldBuf[0][0]);

//打印节点2航向传感器 保持寄存器的数据
        value_HX_DCD_10 = (int16_t)usMRegHoldBuf[1][0];
        rt_kprintf("sensor2_detect: %d \t\r\n", (int16_t)usMRegHoldBuf[1][0]);

//打印节点3左横滚传感器 保持寄存器的数据
        value_ZHG_DCD_10 = (int16_t)usMRegHoldBuf[2][0];
        rt_kprintf("sensor3_detect: %d \t\r\n", (int16_t)usMRegHoldBuf[2][0]);

//打印节点4右横滚传感器 保持寄存器的数据
        value_YHG_DCD_10 = usMRegHoldBuf[3][0];
        rt_kprintf("sensor4_detect: %d \t\r\n", (int16_t)usMRegHoldBuf[3][0]);*/

//打印节点5 拉力传感器 保持寄存器的数据
        value_PULL_DLM_20 = usMRegHoldBuf[5][0];
        rt_kprintf("sensor5_detect: %d \t\r\n", usMRegHoldBuf[5][0]);

//打印时钟节点
        rt_kprintf("tick is %d\r\n",rt_tick_get());

/* Record the number of errors */
        if (error_code != MB_MRE_NO_ERR)
        {
            error_count++;
            rt_kprintf("error_count : %d \n",error_count);
            rt_kprintf("error_code %d\r\n",error_code);
        }
        is_got = 1;

rt_thread_delay(100);
    }
}

static void mb_msg_get(void *parameter)
{
    char mb_get_buf[05][64];

while(1)
    {
        if (is_got)
        {
            //置零
            //memset(mb_get_buf, 0, 320);
/*          //提取数据
            sprintf(mb_get_buf[Displacement_sensor01_SLAVE_ADDR - 1],
                    usMRegHoldBuf[Displacement_sensor01_SLAVE_ADDR - 1][MB_READ_REG_NUM_01]);*/

}
        rt_thread_mdelay(5 * RT_TICK_PER_SECOND);
   }
 }

static void mb_master_poll(void *parameter)
{
    //MB初始化  内部已定义停止位，当前为停止位2；
    eMBMasterInit(MB_RTU, PORT_NUM, PORT_BAUDRATE, PORT_PARITY);
    eMBMasterEnable();

while (1)
    {
        eMBMasterPoll();
        rt_thread_mdelay(MB_POLL_CYCLE_MS);
    }
}

static int TDM_TMD_modbus(int argc, char **argv)
{
    static rt_uint8_t is_init = 0;
    rt_thread_t tid1 = RT_NULL, tid2 = RT_NULL,tid3 = RT_NULL;

if (is_init > 0)
    {
        rt_kprintf("sample is running\n");
        return -RT_ERROR;
    }
    tid1 = rt_thread_create("md_m_poll", mb_master_poll, RT_NULL, 512, MB_POLL_THREAD_PRIORITY, 10);
    if (tid1 != RT_NULL)
    {
        rt_thread_startup(tid1);
    }
    else
    {
        goto __exit;
    }

tid2 = rt_thread_create("md_m_send", send_thread_entry, RT_NULL, 512, MB_SEND_THREAD_PRIORITY, 10);
    if (tid2 != RT_NULL)
    {
        rt_thread_startup(tid2);
    }
    else
    {
        goto __exit;
    }

tid3 = rt_thread_create("mb_msg_get", mb_msg_get, RT_NULL, 2048, 13, 10);
    if (tid3 != RT_NULL)
    {
        rt_thread_startup(tid3);

}
    else
    {
        goto __exit;
    }

is_init = 1;
    return RT_EOK;

//退出
__exit:
    if (tid1)
        rt_thread_delete(tid1);
    if (tid2)
        rt_thread_delete(tid2);
    if (tid3)
        rt_thread_delete(tid3);

return -RT_ERROR;
}
//导出命令行
MSH_CMD_EXPORT(TDM_TMD_modbus, run a TDM_DTECT sample);
//开机启动
//INIT_APP_EXPORT(TDM_TMD_modbus);
```
## 实验现象
![image.png](https://oss-club.rt-thread.org/uploads/20220118/7abf8e2915fec9175961be4c83fdd262.png.webp)