Estou vendo algumas pessoas com dúvidas em como comunicar o ESP-32 com o ScadaBr.
Vou colocar aqui um exemplo bem simples que utilizei de teste e funcionou muito bem para mim.
Encontrei este exemplo aqui:
http://en.trialcommand.com/blog/esp8266-slave-modbus-tcpip-no-libraries/
Código
#include <WiFi.h>
#include <Ultrasonic.h>
Ultrasonic sensor(4, 5, 40000UL);
double distance;
const char* ssid = “nome_do_wifi”;
const char* password = “senha_do_wifi”;
int ModbusTCP_port = 502;
//////// Required for Modbus TCP / IP /// Requerido para Modbus TCP/IP /////////
#define maxInputRegister 20
#define maxHoldingRegister 20
#define MB_FC_NONE 0
#define MB_FC_READ_REGISTERS 3 //implemented
#define MB_FC_WRITE_REGISTER 6 //implemented
#define MB_FC_WRITE_MULTIPLE_REGISTERS 16 //implemented
//
// MODBUS Error Codes
//
#define MB_EC_NONE 0
#define MB_EC_ILLEGAL_FUNCTION 1
#define MB_EC_ILLEGAL_DATA_ADDRESS 2
#define MB_EC_ILLEGAL_DATA_VALUE 3
#define MB_EC_SLAVE_DEVICE_FAILURE 4
//
// MODBUS MBAP offsets
//
#define MB_TCP_TID 0
#define MB_TCP_PID 2
#define MB_TCP_LEN 4
#define MB_TCP_UID 6
#define MB_TCP_FUNC 7
#define MB_TCP_REGISTER_START 8
#define MB_TCP_REGISTER_NUMBER 10
byte ByteArray[260];
unsigned int MBHoldingRegister[maxHoldingRegister];
WiFiServer MBServer(ModbusTCP_port);
int LED_BUILTIN = 2;
void setup() {
pinMode(LED_BUILTIN, OUTPUT);
Serial.begin(9600);
delay(100) ;
WiFi.begin(ssid, password);
delay(100) ;
Serial.println(".");
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
MBServer.begin();
Serial.println("Conectado ");
Serial.print(“ESP32 Slave Modbus TCP/IP “);
Serial.print(WiFi.localIP());
Serial.print(”:”);
Serial.println(String(ModbusTCP_port));
Serial.println(“Modbus TCP/IP Online”);
}
void loop() {
distancia();
// Check if a client has connected // Modbus TCP/IP
WiFiClient client = MBServer.available();
if (!client) {
return;
}
boolean flagClientConnected = 0;
byte byteFN = MB_FC_NONE;
int Start;
int WordDataLength;
int ByteDataLength;
int MessageLength;
// Modbus TCP/IP
while (client.connected()) {
if(client.available())
{
flagClientConnected = 1;
int i = 0;
while(client.available())
{
ByteArray[i] = client.read();
i++;
}
client.flush();
///////// Holding Register [0] A [9] = 10 Holding Registers Escritura
///////// Holding Register [0] A [9] = 10 Holding Registers Writing
MBHoldingRegister[0] = distance * 100;
MBHoldingRegister[1] = random(0,12);
MBHoldingRegister[2] = random(0,12);
MBHoldingRegister[3] = random(0,12);
MBHoldingRegister[4] = random(0,12);
MBHoldingRegister[5] = random(0,12);
MBHoldingRegister[6] = random(0,12);
MBHoldingRegister[7] = random(0,12);
MBHoldingRegister[8] = random(0,12);
MBHoldingRegister[9] = random(0,12);
///////// Holding Register [10] A [19] = 10 Holding Registers Lectura
///// Holding Register [10] A [19] = 10 Holding Registers Reading
int Temporal[10];
Temporal[0] = MBHoldingRegister[10];
Temporal[1] = MBHoldingRegister[11];
Temporal[2] = MBHoldingRegister[12];
Temporal[3] = MBHoldingRegister[13];
Temporal[4] = MBHoldingRegister[14];
Temporal[5] = MBHoldingRegister[15];
Temporal[6] = MBHoldingRegister[16];
Temporal[7] = MBHoldingRegister[17];
Temporal[8] = MBHoldingRegister[18];
Temporal[9] = MBHoldingRegister[19];
/// Enable Output LED
digitalWrite(LED_BUILTIN, MBHoldingRegister[14] );
//// debug
for (int i = 0; i < 10; i++) {
Serial.print("[");
Serial.print(i);
Serial.print("] ");
Serial.print(Temporal[i]);
}
Serial.println("");
//// rutine Modbus TCP
byteFN = ByteArray[MB_TCP_FUNC];
Start = word(ByteArray[MB_TCP_REGISTER_START],ByteArray[MB_TCP_REGISTER_START+1]);
WordDataLength = word(ByteArray[MB_TCP_REGISTER_NUMBER],ByteArray[MB_TCP_REGISTER_NUMBER+1]);
}
// Handle request
switch(byteFN) {
case MB_FC_NONE:
break;
case MB_FC_READ_REGISTERS: // 03 Read Holding Registers
ByteDataLength = WordDataLength * 2;
ByteArray[5] = ByteDataLength + 3; //Number of bytes after this one.
ByteArray[8] = ByteDataLength; //Number of bytes after this one (or number of bytes of data).
for(int i = 0; i < WordDataLength; i++)
{
ByteArray[ 9 + i * 2] = highByte(MBHoldingRegister[Start + i]);
ByteArray[10 + i * 2] = lowByte(MBHoldingRegister[Start + i]);
}
MessageLength = ByteDataLength + 9;
client.write((const uint8_t *)ByteArray,MessageLength);
byteFN = MB_FC_NONE;
break;
case MB_FC_WRITE_REGISTER: // 06 Write Holding Register
MBHoldingRegister[Start] = word(ByteArray[MB_TCP_REGISTER_NUMBER],ByteArray[MB_TCP_REGISTER_NUMBER+1]);
ByteArray[5] = 6; //Number of bytes after this one.
MessageLength = 12;
client.write((const uint8_t *)ByteArray,MessageLength);
byteFN = MB_FC_NONE;
break;
case MB_FC_WRITE_MULTIPLE_REGISTERS: //16 Write Holding Registers
ByteDataLength = WordDataLength * 2;
ByteArray[5] = ByteDataLength + 3; //Number of bytes after this one.
for(int i = 0; i < WordDataLength; i++)
{
MBHoldingRegister[Start + i] = word(ByteArray[ 13 + i * 2],ByteArray[14 + i * 2]);
}
MessageLength = 12;
client.write((const uint8_t *)ByteArray,MessageLength);
byteFN = MB_FC_NONE;
break;
}
}
}
void distancia() {
distance = sensor.distanceRead(); //sem especificar a unidade retorna o timing
distance = distance / 28 / 2;
Serial.println(“Distancia: “);
Serial.print(distance);
Serial.println(” cm”);
delay(1000);
}