关于Arduino与信捷PLC的modbus问题
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; //!< 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;
unsigned long u32wait;
void setup() {
// telegram 0: read registers--------du han shu
telegram.u8id = 4; // slave address
telegram.u8fct = 3; // function code (this one is registers read)
telegram.u16RegAdd = 5; // start address in slave
telegram.u16CoilsNo = 2; // number of elements (coils or registers) to read
telegram.au16reg = au16data; // pointer to a memory array in the Arduino
// telegram 1: write a single register----xie han shu
telegram.u8id = 3; // slave address
telegram.u8fct = 6; // function code (this one is write a single register)
telegram.u16RegAdd = 2; // start address in slave
telegram.u16CoilsNo = 10; // number of elements (coils or registers) to read
telegram.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 ); // 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 = 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 直接用格西对plc调试啊~不要自己写程序先 maxims 发表于 2016-5-18 08:18 static/image/common/back.gif
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 学习学习学习学习
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