关于Arduino与信捷PLC的modbus问题

15275285755

我现在正在做ARDUINO与国产的信捷PLC的modbus协议通讯。

                     用的是ttl232转RS232的模块，然后将TX RX，等线连接好后。

       在PLC处进行了编辑，写了一个读程序和一个写程序，然后用格西烽火软件通过USB串口线看到确实有数据出来

       然后我用了下面的这一个程序。

#include <ModbusRtu.h>

uint16_t au16data[16]; //!< data array for modbus network sharing
uint8_t u8state; //!< machine state
uint8_t u8query; //!< pointer to message query

/**
*  Modbus object declaration
*  u8id : node id = 0 for master, = 1..247 for slave
*  u8serno : serial port (use 0 for Serial)
*  u8txenpin : 0 for RS-232 and USB-FTDI
*               or any pin number > 1 for RS-485
*/
Modbus master(0,0,0); // this is master and RS-232 or USB-FTDI

/**
* This is an structe which contains a query to an slave device
*/
modbus_t telegram[2];

unsigned long u32wait;

void setup() {
  // telegram 0: read registers--------du han shu
  telegram[0].u8id = 4; // slave address
  telegram[0].u8fct = 3; // function code (this one is registers read)
  telegram[0].u16RegAdd = 5; // start address in slave
  telegram[0].u16CoilsNo = 2; // number of elements (coils or registers) to read
  telegram[0].au16reg = au16data; // pointer to a memory array in the Arduino

  // telegram 1: write a single register----xie han shu
  telegram[1].u8id = 3; // slave address
  telegram[1].u8fct = 6; // function code (this one is write a single register)
  telegram[1].u16RegAdd = 2; // start address in slave
  telegram[1].u16CoilsNo = 10; // number of elements (coils or registers) to read
  telegram[1].au16reg = au16data; // pointer to a memory array in the Arduino
       
  master.begin( 19200 ); // baud-rate at 19200
  master.setTimeOut( 5000 ); // if there is no answer in 5000 ms, roll over
  u32wait = millis() + 100;
  u8state = u8query = 1;
}

void loop() {
  switch( u8state ) {
  case 0:
    if (millis() > u32wait) u8state++; // wait state
    break;
  case 1:
    master.query( telegram[u8query] ); // send query (only once)
    u8state++;
        u8query++;
        if (u8query > 2) u8query = 0;
    break;
  case 2:
    master.poll(); // check incoming messages
    if (master.getState() == COM_IDLE) {
      u8state = 0;
      u32wait = millis() + 1000;
    }
    break;
  }

  au16data[4] = analogRead(1);
  
}



结果我无论如何也无法进行通讯，希望有大神帮忙看看

maxims

直接用格西对plc调试啊~不要自己写程序先

15275285755

maxims 发表于 2016-5-18 08:18
直接用格西对plc调试啊~不要自己写程序先

我也是按照格式来的，可是怎么调试也是对不上通讯

原野动力

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