public MBMessage DealRequest(MBConnect c, MBMessage req)
{
MBMessage resp;
if (req.FC == 0x01)
{
resp = AckReadCoil(req);
}
else if (
req.FC == 0x05)
{
resp = AckWriteCoil(req);
}
else
{
resp = new MBMessage(req);
resp.FC = (byte)(0x80 | req.FC);
resp.SetBody(new byte[] { MBException.E01_ILLEGAL_FUNCTION });
}
return resp;
}
private MBMessage AckReadCoil(MBMessage req)
{
MBMessage resp = new MBMessage(req);
/**
* req:
* Byte 1-2:Reference number
* Byte 3-4:Bit count (1-2000)
* resp:
* Response
* Byte 1: Byte count of response (B=(bit count+7)/8)
* Byte 2-(B+1):Bit values (least significant bit is first coil!)"
*/
ushort refNum = req.GetWord(0);
ushort bitCount = req.GetWord(2);
if (_cms.IsValidRegAddress((byte)refNum))
{
byte[] byteValues = _cms.MB_ReadCoils(refNum, bitCount);
// 写入.
var bcnt = byteValues.Length;
resp.SetBodySize((ushort)(bcnt + 1));
resp.SetByte(0, (byte)bcnt);
for (byte i = 0; i < bcnt; i++)
{
resp.SetByte(i + 1, byteValues[i]);
}
}
else
{
// Error Response.
// Byte 0:FC = 81 (hex)
// Byte 1:exception code = 01 or 02
resp.FC = 0x82;
resp.SetBody(new byte[] { MBException.E02_ILLEGAL_DATA_ADDRESS });
}
return resp;
}
/* WriteCoil
REQ:
Byte 0:FC = 05
Byte 1-2: Reference number
Byte 3:= FF to turn coil ON, =00 to turn coil OFF
Byte 4:= 00
Resp:
Byte 1-2:Reference number
Byte 3:= FF to turn coil ON, =00 to turn coil OFF (echoed)
Byte 4:= 00"
*/
private MBMessage AckWriteCoil(MBMessage req)
{
MBMessage resp = new MBMessage(req); // copy header
ushort refNum = req.GetWord(0); //
byte val = req.GetByte(2);
byte result = _cms.MB_WriteCoil(refNum, val); // exception
if (MBException.MB_SUCCESS == result)
{
// OK, return resp
}
else
{
// ERROR
resp.FC = 0x85;
resp.SetBody(new byte[] { result });
}
return resp;
}