RS 485 Impossible to communicate with other device

Good morning,

I try to use RS 485 to communicate between my IND.I/O (Master) and on other device (Slave) to have power and tempretures, but it doesn't worked. I precise, my code work well with an arduino Uno.

I leave one switch on 120 ohm with the jumper (I remove the two others 560 ohm) , the pin TxEnablePin is 9, Name of the port is Serial...

I d'on't understant what's happen. If anybody can help me that will be nice. 

Thank a lot for your help.

Olivier 

*************************************************************

#include <SimpleModbusMaster.h>

//////////////////// Port information ///////////////////
#define baud 9600
#define timeout 1000
#define polling 200 // the scan rate
#define retry_count 10

// used to toggle the receive/transmit pin on the driver
#define TxEnablePin 9 

#define LED 9

// The total amount of available memory on the master to store data
#define TOTAL_NO_OF_REGISTERS 8

// This is the easiest way to create new packets
// Add as many as you want. TOTAL_NO_OF_PACKETS
// is automatically updated.
enum
{
  PACKET1,
  PACKET2, 
  PACKET3, 
  TOTAL_NO_OF_PACKETS // leave this last entry
};

// Create an array of Packets to be configured
Packet packets[TOTAL_NO_OF_PACKETS];

// Masters register array
unsigned int regs[TOTAL_NO_OF_REGISTERS];
unsigned long previousMillis;

// Fct de paramétrage
// ******************
void setup()
{
//  SerialUSB.begin(115200);
//  SerialUSB.println("setup()");
  
  // init : BUS RS 485
  // ********************
  // Initialize each packet
 
  modbus_construct(&packets[PACKET1], 2, READ_INPUT_REGISTERS, 61, 1, 0);       //PAC : [reg. 61] recupération de la puissance instantannée en W
  modbus_construct(&packets[PACKET2], 2, READ_INPUT_REGISTERS, 5, 1, 1);        //PAC : [reg. 5] recupération AC unit Temperature reference (de 10° à 42°) ou température de la PAC servant de reférence à la modulation de la puissance electrique
  modbus_construct(&packets[PACKET3], 2, READ_HOLDING_REGISTERS, 4, 1, 2);      //PAC : [reg. 4] [LECTURE] AC unit Temperature setpoint (de 16° à 30°) ou température a atteindre par la PAC.  

  // Initialize the Modbus Finite State Machine
  modbus_configure(&Serial, baud, SERIAL_8N2, timeout, polling, retry_count, TxEnablePin, packets, TOTAL_NO_OF_PACKETS, regs); // Init du protocole BUS RS 485
 
}

void loop()
{
    modbus_update();
    if (millis() - previousMillis > 500) {
      SerialUSB.println(String(regs[0]/1.0,1)  + "W");
      SerialUSB.println(String(regs[1]/1.0, 0)   + "°C"); 
      SerialUSB.println(String(regs[2]/1.0, 0)   + "°C"); 
    previousMillis = millis();
    }
}

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Olive Bai

Olive Bai

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Asked on 5/4/21, 2:11 PM

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