// +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
// +
// +    FileName:   ModBus.cpp          Author:     S.Hammond
// +
// +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
// +
// +    Defines and class definition for the ModBus class,
// +    see ModBus.cpp for more infomation
// +
// +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

#ifndef _MODBUS_H_
#define _MODBUS_H_

#include "CommsDevice.h"

// +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

#define MODBUS_READ_SINGLE      3
#define MODBUS_WRITE_SINGLE     6

#define MODBUS_CAL_TEMP         0x01c
#define MODBUS_CAL_SP1          0x07f
#define MODBUS_CAL_SECURITY     0x300
#define MODBUS_CAL_DISPLAY      0x306
#define MODBUS_CAL_LEVC_ADDR    0x3d5
#define MODBUS_CAL_LEVC_BAUD    0x3d6
#define MODBUS_CAL_MODEL        0x4fc
#define MODBUS_CAL_ENTERPROG    0x1500
#define MODBUS_CAL_EXITPROG     0x1600

#define MODBUS_CAL_ENTERBYTE    0x05
#define MODBUS_CAL_EXITBYTE     0x06

#define MODBUS_MINIMUM_LENGTH   4
#define MESSAGE_BUFFER_LENGTH   256

#define MODBUS_CAL_POLL         2000
#define MODBUS_REPLY_MAX_WAIT   25

typedef struct sModBusHeader    MODBUSHEADER;
typedef struct sModBusHeader   *PMODBUSHEADER;

struct sModBusHeader
{   BYTE    SlaveAddr;
    BYTE    Function;
    BYTE    bData[1];
};

class CModBus
{
public:
    CModBus();
    ~CModBus();

    void    ModReadSingle(BYTE Slave,WORD Addr);
    void    ModWriteSingle(BYTE Slave,WORD Addr, WORD Data);
    BOOL    ModEnterProgram(BYTE bSlave);
    BOOL    ModExitProgram(BYTE bSlave);
    BOOL    ValidResponse(void);
    BYTE    GetByte(int Index);
    WORD    GetWord(int Index);
    void    QueryDevice(BYTE Slave,char *Model);
        
protected:
    void    StartMessage(void);
    void    EndMessage(void);
    void    AddByte(BYTE bData);
    void    AddWord(WORD wData);
    void    AddWordLSBFirst(WORD wData);
    void    GenCRC(void);
    void    WriteMessage(void);
    void    ReadMessage(void);

    BYTE    MessageBuffer[MESSAGE_BUFFER_LENGTH];
    PMODBUSHEADER   pMessageHeader;
    int     BufferLength;
    BYTE    ResponseBuffer[MESSAGE_BUFFER_LENGTH];
    PMODBUSHEADER   pResponseHeader;
    int     ResponseLength;


};

#ifdef _MODBUS_C_
       class CModBus    ModBus;
#else
extern class CModBus    ModBus;
#endif

// +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

#endif /* _MODBUS_H_ */