Arduino PLC IDEのメモ

//  Name: Opta_Client

#include 
#include  // ArduinoModbus depends on the ArduinoRS485 library

constexpr auto baudrate { 9600 };

// Calculate preDelay and postDelay in microseconds as per Modbus RTU Specification
// MODBUS over serial line specification and implementation guide V1.02
// Paragraph 2.5.1.1 MODBUS Message RTU Framing
// https://modbus.org/docs/Modbus_over_serial_line_V1_02.pdf
constexpr auto bitduration { 1.f / baudrate };
constexpr auto preDelayBR { bitduration * 9.6f * 3.5f * 1e6 };
constexpr auto postDelayBR { bitduration * 9.6f * 3.5f * 1e6 };
// constexpr auto preDelayBR { bitduration * 10.0f * 3.5f * 1e6 };

void setup() {
    Serial.begin(9600);
    while (!Serial);

    pinMode(LED_D0, OUTPUT);

    Serial.println("Modbus RTU Client");
    delay(10);

    RS485.setDelays(preDelayBR, postDelayBR);

    // Start the Modbus RTU client
    if (!ModbusRTUClient.begin(baudrate, SERIAL_8N1)) {
        Serial.println("Failed to start Modbus RTU Client!");
        while (1);
    }
}

void loop() {
  digitalWrite(LED_D0, HIGH);
  delay(1000);
  digitalWrite(LED_D0, LOW);
  delay(1000);

    readHoldingRegisterValues();

    delay(5000);
    Serial.println();
}


/**
  Reads Holding Register values from the server under specified address.
*/
void readHoldingRegisterValues() {
    Serial.print("Reading Holding Register values ...");

    // Read HOLDING Register values from (server) id = 2, address 0x2000 2bytes?
    if (!ModbusRTUClient.requestFrom(2, HOLDING_REGISTERS, 0x2000, 1)) {
        Serial.print("failed! ");
        Serial.println(ModbusRTUClient.lastError());
    } else {
        Serial.println("success");

        while (ModbusRTUClient.available()) {
            Serial.println("オムロンE5CN-H");
            Serial.print(round(ModbusRTUClient.read() / 10.0),1);
            Serial.println("`C");
        }
        Serial.println();
    }

    Serial.print("Reading Holding Register values ...");
    // Read HOLDING Register values from (server) id = 1, address 0x0080 2bytes?
    if (!ModbusRTUClient.requestFrom(1, HOLDING_REGISTERS, 0x0080, 1)) {
        Serial.print("failed! ");
        Serial.println(ModbusRTUClient.lastError());
    } else {
        Serial.println("success");

        while (ModbusRTUClient.available()) {
            Serial.println("パナソニックKT-7");
            Serial.print(round(ModbusRTUClient.read() / 10.0),1);
            Serial.println("`C");
        }
        Serial.println();
    }
}