Modbus Object Instantiation/Initialization

Functions
void	Modbus::begin (long u32speed)
	Initialize class object.
void	Modbus::begin (long u32speed, uint8_t u8config)
	Initialize class object.
void	Modbus::begin (SoftwareSerial *sPort, long u32speed)
	Initialize class object.
uint8_t	Modbus::getID ()
	get slave ID between 1 and 247
	Modbus::Modbus ()
	Default Constructor for Master through Serial.
void	Modbus::setID (uint8_t u8id)
	write new ID for the slave
void	Modbus::setTimeOut (uint16_t u16timeout)
	write communication watch-dog timer

Detailed Description

Function Documentation

begin() [1/3]

void Modbus::begin

(

long

u32speed

)

Initialize class object.

Sets up the serial port using specified baud rate. Call once class has been instantiated, typically within setup().

See also

http://arduino.cc/en/Serial/Begin#.Uy4CJ6aKlHY

Parameters

speed

baud rate, in standard increments (300..115200)

Definition at line 298 of file ModbusRtu.h.

{
 
    switch (u8serno)
    {
#if defined(UBRR1H)
    case 1:
        port = &Serial1;
        break;
#endif
 
#if defined(UBRR2H)
    case 2:
        port = &Serial2;
        break;
#endif
 
#if defined(UBRR3H)
    case 3:
        port = &Serial3;
        break;
#endif
    case 0:
    default:
 
        port = &Serial;
        break;
    }
 
    port->begin(u32speed);
    if (u8txenpin > 1) // pin 0 & pin 1 are reserved for RX/TX
    {
        // return RS485 transceiver to transmit mode
        RS485_DIR_REG |= RS485_PIN_DE | RS485_PIN_RE;
        RS485_CLEAR_DE;
        RS485_CLEAR_RE;
        // pinMode(u8txenpin, OUTPUT);
        // digitalWrite(u8txenpin, LOW);
    }
 
    while (port->read() >= 0)
        ;
    u8lastRec = u8BufferSize = 0;
    u16InCnt = u16OutCnt = u16errCnt = 0;
}

begin() [2/3]

void Modbus::begin	(	long	u32speed,
		uint8_t	u8config )

Initialize class object.

Sets up the serial port using specified baud rate. Call once class has been instantiated, typically within setup().

See also

http://arduino.cc/en/Serial/Begin#.Uy4CJ6aKlHY

Parameters

speed	baud rate, in standard increments (300..115200)
config	data frame settings (data length, parity and stop bits)

Definition at line 395 of file ModbusRtu.h.

{
 
    switch (u8serno)
    {
#if defined(UBRR1H)
    case 1:
        port = &Serial1;
        break;
#endif
 
#if defined(UBRR2H)
    case 2:
        port = &Serial2;
        break;
#endif
 
#if defined(UBRR3H)
    case 3:
        port = &Serial3;
        break;
#endif
    case 0:
    default:
        port = &Serial;
        break;
    }
 
    port->begin(u32speed, u8config);
    if (u8txenpin > 1) // pin 0 & pin 1 are reserved for RX/TX
    {
        // return RS485 transceiver to transmit mode
        RS485_DIR_REG |= RS485_PIN_DE | RS485_PIN_RE;
        RS485_CLEAR_DE;
        RS485_CLEAR_RE;
        // pinMode(u8txenpin, OUTPUT);
        // digitalWrite(u8txenpin, LOW);
    }
 
    while (port->read() >= 0)
        ;
    u8lastRec = u8BufferSize = 0;
    u16InCnt = u16OutCnt = u16errCnt = 0;
}

begin() [3/3]

void Modbus::begin	(	SoftwareSerial *	sPort,
		long	u32speed )

Initialize class object.

Sets up the software serial port using specified baud rate and SoftwareSerial object. Call once class has been instantiated, typically within setup().

Parameters

speed	*softPort, pointer to SoftwareSerial class object
speed	baud rate, in standard increments (300..115200)

Definition at line 360 of file ModbusRtu.h.

{
 
    softPort = sPort;
 
    softPort->begin(u32speed);
 
    if (u8txenpin > 1) // pin 0 & pin 1 are reserved for RX/TX
    {
        // return RS485 transceiver to transmit mode
        RS485_DIR_REG |= RS485_PIN_DE | RS485_PIN_RE;
        RS485_CLEAR_DE;
        RS485_CLEAR_RE;
        // pinMode(u8txenpin, OUTPUT);
        // digitalWrite(u8txenpin, LOW);
    }
 
    while (softPort->read() >= 0)
        ;
    u8lastRec = u8BufferSize = 0;
    u16InCnt = u16OutCnt = u16errCnt = 0;
}

getID()

uint8_t Modbus::getID

(

)

get slave ID between 1 and 247

Method to read current slave ID address.

Returns

u8id current slave address between 1 and 247

Definition at line 477 of file ModbusRtu.h.

{
    return this->u8id;
}

Modbus()

Modbus::Modbus

(

)

Default Constructor for Master through Serial.

Definition at line 228 of file ModbusRtu.h.

{
    init(0, 0, 0);
    debugSend = false;
}

setID()

void Modbus::setID

(

uint8_t

u8id

)

write new ID for the slave

Method to write a new slave ID address.

Parameters

u8id	new slave address between 1 and 247

Definition at line 462 of file ModbusRtu.h.

{
    if ((u8id != 0) && (u8id <= 247))
    {
        this->u8id = u8id;
    }
}

setTimeOut()

void Modbus::setTimeOut

(

uint16_t

u16timeOut

)

write communication watch-dog timer

Initialize time-out parameter.

Call once class has been instantiated, typically within setup(). The time-out timer is reset each time that there is a successful communication between Master and Slave. It works for both.

Parameters

time-out

value (ms)

Definition at line 493 of file ModbusRtu.h.

{
    this->u16timeOut = u16timeOut;
}