/*@!Encoding:1252*/
variables
{
	// A normal Modbus Application Header. Every Modbus Packet begins with these 7 (+FuncCode) Bytes
	_align(1) struct ModbusApHeader
	{
		word TxID;
		word Protocol;
		word Length;
		byte UnitID;
		byte FuncCode;
	};
	// Read Data from the host. We only need the start address and the number of bits/registers we want to read
	_align(1) struct ModbusReqRead
	{
		struct ModbusApHeader Header;
		word Address;
		word Count;
	};
	// Write a single value to a bit/register
	_align(1) struct ModbusReqWriteSingle
	{
		struct ModbusApHeader Header;
		word Address;
		word Value;
	};
	// Write several values to a bit/register starting with Address
	_align(1) struct ModbusReqWriteBits
	{
		struct ModbusApHeader Header;
		word Address;
		word Count;
		byte ByteCount;
		byte Data[246];		// Max length: 1968 bits
	};
	// Write several values to bits starting with Address
	_align(1) struct ModbusReqWriteRegisters
	{
		struct ModbusApHeader Header;
		word Address;
		word Count;
		byte ByteCount;
		word Data[123];		// Max length: 123 registers
	};
	// Write AND and OR masks to a holding register
	_align(1) struct ModbusReqWriteMasks
	{
		struct ModbusApHeader Header;
		word Address;
		word And;
		word Or;
	};
	// Read and write multiple registers
	_align(1) struct ModbusReqReadWriteRegisters
	{
		struct ModbusApHeader Header;
		word ReadAddress;
		word ReadCount;
		word WriteAddress;
		word WriteCount;
		byte ByteCount;
		word Data[121];		// Max length: 123-2 registers
	};


	// Receive several bit values
	_align(1) struct ModbusResReceiveBits
	{
		struct ModbusApHeader Header;
		byte ByteCount;
		byte Data[250];		// Max length: 2000 bits
	};
	// Receive several register values
	_align(1) struct ModbusResReceiveRegisters
	{
		struct ModbusApHeader Header;
		byte ByteCount;
		word Data[125];		// Max length: 125 registers
	};
	// Confirm the write of a single bit/register
	_align(1) struct ModbusResConfirmSingle
	{
		struct ModbusApHeader Header;
		word Address;
		int Value;
	};
	// Confirm the write of several bits/registers
	_align(1) struct ModbusResConfirmMultiple
	{
		struct ModbusApHeader Header;
		word Address;
		word Count;
	};
	// Confirm the write of AND and OR mask
	_align(1) struct ModbusResConfirmMasks
	{
		struct ModbusApHeader Header;
		word Address;
		word And;
		word Or;
	};



	enum ModbusRequestError
	{
		Exception,
		Timeout 
    };
	enum ModbusException
	{
		None = 0x00,
		IllegalFuncCode = 0x01,
		IllegalDataAddress = 0x02,
		IllegalDataValue = 0x03,
		ServerFailure = 0x04,
		Acknowledge = 0x05,
		ServerBusy = 0x06,
		GatewayPathsNA = 0x0A,
		TargetOffline = 0x0B
	};
}