communication.h File Reference

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Detailed Description

Communication.

#include <plcmodem.h>

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Data Structures
class	Communication
	Communication class. More...
class	PLC_ERROR
Defines
#define	SERIAL_PORT   "/dev/ttyS0"
	Serial Port.
#define	MARCA   1
	Defines a constant for one.
#define	ESPACO   0
	Defines a constant for zero.
#define	MAX_NUM_NACK   0x07
	Defines the maximum number of NAK signals for a specific data block.
#define	MAX_NUM_WAIT   0x0C
	Defines the maximum number of WAIT signals for a specific data block.
#define	MAX_NUM_REP   0x07
	Defines the maximum number of repetitions for a specific command to be transmitted.
#define	OK   1
	Defines a constant for OK.
#define	NOK   0
	Defines a constant for NOK.
#define	ETIMEOUT   -2
	Defines an error code for timeout during communication.
Enumerations
enum	COMM_STATE {   DISCONNECTED = 0xA,   TRYING_CONNECTION = 0xB,   CONNECTED = 0xC,   COMMUNICATION = 0xD,   END_CONNECTION = 0xE }
	Defines the possible states in the FSM for the communication. More...
enum	COMM_SIGNAL {   ENQ = 0x05,   ACK = 0x06,   NAK = 0x15,   WAIT = 0x10 }
	Defines the bytes (signals) used in the communication. More...
Functions
unsigned	calcularCRC (unsigned char *buffer, int numBytes)
	a normal function to calculate the CRC of the data to be trasmitted.
Variables
const int	MAX_BUFFER_RESPOSTA = 258
	Defines the maximum number of bytes permitted in the answer frame.
const int	MAX_BUFFER_DADOS = 66
	Defines the maximum number of bytes permitted in the command frame.

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Enumeration Type Documentation

enum COMM_SIGNAL

Defines the bytes (signals) used in the communication. Enumeration values: ENQ  ENQ byte: used for synchronization. ACK  ACK byte: means that the last answer transmitted was correctly received. NAK  NAK byte: means that the last data block was completely received, but with a CRC error. WAIT  WAIT byte: used to delay the transmition.

enum COMM_STATE

Defines the possible states in the FSM for the communication. Enumeration values: DISCONNECTED  Disconected state: devices do not receive neither transmit data. TRYING_CONNECTION  Trying_connection state: devices are trying to establish communication. CONNECTED  Connected state: communication is established. COMMUNICATION  Communication state: devices exchanging data. END_CONNECTION  Termination state: finishes FSM execution.

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Function Documentation

unsigned calcularCRC (  unsigned char *  buffer, int  numBytes )

a normal function to calculate the CRC of the data to be trasmitted. Parameters: buffer  data used to calculate the CRC. numBytes  the number of bytes to take into account for the CRC value.

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