modbus poll怎么读寄存器数据

好的，这里提供一个基于STM32的FreeModbus从站读寄存器数据的代码示例供参考： ```c /* FreeModbus includes */ #include "mb.h" #include "mbutils.h" /* STM32 includes */ #include "stm32f10x.h" /* Define the number of registers */ #define REG_INPUT_NREGS 4 #define REG_HOLDING_NREGS 8 /* Define the start addresses of the input and holding registers */ #define REG_INPUT_START 1000 #define REG_HOLDING_START 2000 /* Define the buffer sizes */ #define BUF_SIZE 64 /* Define the USART baud rate */ #define USART_BAUDRATE 9600 /* Define the USART port */ #define USART_PORT USART1 /* Define the GPIO pins for the USART */ #define USART_GPIO GPIOA #define USART_TX_PIN GPIO_Pin_9 #define USART_RX_PIN GPIO_Pin_10 /* Define the GPIO pins for the LED */ #define LED_GPIO GPIOC #define LED_PIN GPIO_Pin_13 /* Define the slave address */ #define SLAVE_ADDRESS 0x01 /* Define the modbus mode (ASCII or RTU) */ #define MODBUS_MODE MB_RTU /* Define the modbus UART parameters */ #define MODBUS_UART USART1 #define MODBUS_UART_BAUD 9600 #define MODBUS_UART_PARITY USART_Parity_No #define MODBUS_UART_STOP USART_StopBits_1 #define MODBUS_UART_DATA USART_WordLength_8b /* Define the modbus timer parameters */ #define MODBUS_TIM TIM2 #define MODBUS_TIM_FREQ 1000000 #define MODBUS_TIM_PRESC 71 #define MODBUS_TIM_PERIOD 100 /* Define the modbus timer interrupt priority */ #define MODBUS_TIM_IRQ_PRI 5 /* Define the modbus timer interrupt flag */ #define MODBUS_TIM_IRQ_FLAG TIM_IT_Update /* Define the modbus timer interrupt function */ #define MODBUS_TIM_IRQ_FUNC TIM2_IRQHandler /* Define the modbus timer interrupt handler */ #define MODBUS_TIM_IRQ_HANDLER MODBUS_TIM_IRQ_FUNC /* Define the modbus timer interrupt vector */ #define MODBUS_TIM_IRQ_VECTOR TIM2_IRQn /* Define the modbus timer interrupt vector table entry */ #define MODBUS_TIM_IRQ_ENTRY MODBUS_TIM_IRQ_HANDLER /* Define the modbus timer interrupt enable */ #define MODBUS_TIM_IRQ_EN TIM_IT_Update /* Define the modbus timer interrupt disable */ #define MODBUS_TIM_IRQ_DIS 0 /* Define the modbus timer initialization function */ void modbus_timer_init( void ); /* Define the modbus timer interrupt function */ void modbus_timer_irq( void ); /* Define the modbus initialization function */ void modbus_init( void ); /* Define the modbus polling function */ void modbus_poll( void ); /* Define the input register buffer */ USHORT usRegInputStart = REG_INPUT_START; USHORT usRegInputBuf[REG_INPUT_NREGS]; /* Define the holding register buffer */ USHORT usRegHoldingStart = REG_HOLDING_START; USHORT usRegHoldingBuf[REG_HOLDING_NREGS]; /* Define the USART buffer */ uint8_t ucUSARTBuf[BUF_SIZE]; /* Define the USART buffer length */ uint16_t usUSARTLen = 0; /* Define the LED state */ uint8_t ucLEDState = 0; /* Define the main function */ int main( void ) { /* Initialize the system clock */ SystemInit(); /* Initialize the GPIO pins for the USART */ RCC_APB2PeriphClockCmd( RCC_APB2Periph_GPIOA, ENABLE ); GPIO_InitTypeDef GPIO_InitStruct; GPIO_InitStruct.GPIO_Pin = USART_TX_PIN | USART_RX_PIN; GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF_PP; GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz; GPIO_Init( USART_GPIO, &GPIO_InitStruct ); /* Initialize the GPIO pins for the LED */ RCC_APB2PeriphClockCmd( RCC_APB2Periph_GPIOC, ENABLE ); GPIO_InitStruct.GPIO_Pin = LED_PIN; GPIO_InitStruct.GPIO_Mode = GPIO_Mode_Out_PP; GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz; GPIO_Init( LED_GPIO, &GPIO_InitStruct ); /* Initialize the USART port */ RCC_APB2PeriphClockCmd( RCC_APB2Periph_USART1, ENABLE ); USART_InitTypeDef USART_InitStruct; USART_InitStruct.USART_BaudRate = USART_BAUDRATE; USART_InitStruct.USART_WordLength = USART_WordLength_8b; USART_InitStruct.USART_StopBits = USART_StopBits_1; USART_InitStruct.USART_Parity = USART_Parity_No; USART_InitStruct.USART_HardwareFlowControl = USART_HardwareFlowControl_None; USART_InitStruct.USART_Mode = USART_Mode_Rx | USART_Mode_Tx; USART_Init( USART_PORT, &USART_InitStruct ); USART_Cmd( USART_PORT, ENABLE ); /* Initialize the modbus timer */ modbus_timer_init(); /* Initialize the modbus */ modbus_init(); /* Main loop */ while( 1 ) { /* Poll the modbus */ modbus_poll(); /* Toggle the LED */ if( ucLEDState ) { GPIO_WriteBit( LED_GPIO, LED_PIN, Bit_RESET ); ucLEDState = 0; } else { GPIO_WriteBit( LED_GPIO, LED_PIN, Bit_SET ); ucLEDState = 1; } /* Delay */ Delay( 100 ); } } /* Define the modbus timer initialization function */ void modbus_timer_init( void ) { /* Enable the timer clock */ RCC_APB1PeriphClockCmd( RCC_APB1Periph_TIM2, ENABLE ); /* Configure the timer */ TIM_TimeBaseInitTypeDef TIM_InitStruct; TIM_InitStruct.TIM_Prescaler = MODBUS_TIM_PRESC; TIM_InitStruct.TIM_CounterMode = TIM_CounterMode_Up; TIM_InitStruct.TIM_Period = MODBUS_TIM_PERIOD; TIM_InitStruct.TIM_ClockDivision = TIM_CKD_DIV1; TIM_InitStruct.TIM_RepetitionCounter = 0; TIM_TimeBaseInit( MODBUS_TIM, &TIM_InitStruct ); /* Enable the timer interrupt */ NVIC_InitTypeDef NVIC_InitStruct; NVIC_InitStruct.NVIC_IRQChannel = MODBUS_TIM_IRQ_VECTOR; NVIC_InitStruct.NVIC_IRQChannelPreemptionPriority = MODBUS_TIM_IRQ_PRI; NVIC_InitStruct.NVIC_IRQChannelSubPriority = 0; NVIC_InitStruct.NVIC_IRQChannelCmd = ENABLE; NVIC_Init( &NVIC_InitStruct ); /* Enable the timer interrupt flag */ TIM_ITConfig( MODBUS_TIM, MODBUS_TIM_IRQ_FLAG, ENABLE ); /* Start the timer */ TIM_Cmd( MODBUS_TIM, ENABLE ); } /* Define the modbus timer interrupt function */ void modbus_timer_irq( void ) { /* Update the modbus timer */ (void)pxMBPortCBTimerExpired(); } /* Define the modbus initialization function */ void modbus_init( void ) { /* Initialize the modbus */ eMBErrorCode eMBErrorCode = eMBInit( MODBUS_MODE, SLAVE_ADDRESS, MODBUS_UART, MODBUS_UART_BAUD, MODBUS_UART_PARITY, MODBUS_UART_DATA ); if( eMBErrorCode != MB_ENOERR ) { /* Handle the error */ } /* Enable the modbus */ eMBErrorCode = eMBEnable(); if( eMBErrorCode != MB_ENOERR ) { /* Handle the error */ } } /* Define the modbus polling function */ void modbus_poll( void ) { /* Get the number of bytes in the USART buffer */ uint16_t usBytes = USART_GetBytesAvailable( USART_PORT ); /* If there are bytes in the buffer */ if( usBytes > 0 ) { /* Read the bytes from the USART buffer */ USART_Read( USART_PORT, ucUSARTBuf, usBytes ); /* Pass the bytes to the modbus */ eMBErrorCode eMBErrorCode = eMBPoll( ucUSARTBuf, usBytes ); if( eMBErrorCode != MB_ENOERR ) { /* Handle the error */ } } } /* Define the modbus timer interrupt handler */ void MODBUS_TIM_IRQ_HANDLER( void ) { /* Clear the timer interrupt flag */ TIM_ClearITPendingBit( MODBUS_TIM, MODBUS_TIM_IRQ_FLAG ); /* Call the modbus timer interrupt function */ modbus_timer_irq(); } ``` 以上是基于STM32的FreeModbus从站读寄存器数据的代码示例，仅供参考。具体实现需要根据具体的硬件平台和应用场景进行调整。

Modbus Poll 是一款 Modbus 网络调试工具，可以用于测试和调试 Modbus TCP、Modbus ASCII 和 Modbus RTU 设备。如果您要编写 Modbus 寄存器的代码，需要使用 Modbus 库或者 SDK。 在使用 Modbus Poll 时，您可以按照以下步骤操作： 1. 连接 Modbus 设备：在 Modbus Poll 中，点击“连接”按钮，选择 Modbus 设备的连接方式（TCP、RTU 或 ASCII），输入设备的 IP 地址或串口号、波特率、数据位、校验位等连接参数，点击“连接”按钮连接到设备。 2. 选择寄存器：在 Modbus Poll 中，选择要操作的寄存器类型（离散输入、线圈、保持寄存器或输入寄存器），输入寄存器地址和数量，点击“读取”按钮读取寄存器的值。 3. 写入寄存器：在 Modbus Poll 中，选择要操作的寄存器类型（保持寄存器或线圈），输入寄存器地址、数量和值，点击“写入”按钮将值写入寄存器。 需要注意的是，Modbus 寄存器的地址和数量都是以 0 开始的，例如第一个寄存器的地址为 0，第一个寄存器的数量为 1。另外，Modbus 协议规定，每个寄存器的数据长度为 16 位，即两个字节。