/*
?Part?of?Libnodave?a?free?communication?libray?for?Siemens?S7?300/400?via
?the?MPI?adapter?6ES7?972-0CA22-0XAC
?or??MPI?adapter?6ES7?972-0CA33-0XAC
?or??MPI?adapter?6ES7?972-0CA11-0XAC.
?
?（C）?Thomas?Hergenhahn?（thomas.hergenhahn@web.de）?2002..2005

?Libnodave?is?free?software;?you?can?redistribute?it?and/or?modify
?it?under?the?terms?of?the?GNU?Library?General?Public?License?as?published?by
?the?Free?Software?Foundation;?either?version?2?or?（at?your?option）
?any?later?version.

?Libnodave?is?distributed?in?the?hope?that?it?will?be?useful
?but?WITHOUT?ANY?WARRANTY;?without?even?the?implied?warranty?of
?MERCHANTABILITY?or?FITNESS?FOR?A?PARTICULAR?PURPOSE.??See?the
?GNU?Library?General?Public?License?for?more?details.

?You?should?have?received?a?copy?of?the?GNU?Library?General?Public?License
?along?with?this;?see?the?file?COPYING.??If?not?write?to
?the?Free?Software?Foundation?675?Mass?Ave?Cambridge?MA?02139?USA.??
*/
package?org.libnodave;

public?class?IBH_MPIConnection?extends?S7Connection?{
	byte?MPI;

	public?IBH_MPIConnection（PLCinterface?ifa?int?mpi）?{
		super（ifa）;
		this.MPI?=?（byte）?mpi;
		PDUstartIn?=?8?+?7;
		PDUstartOut?=?8?+?7;
	}

	private?int?readPacket（）?{
		int?res?=?iface.read（msgIn?0?4）;
		if?（res?==?4）?{
			int?len?=?0x100?*?msgIn[2]?+?msgIn[3];
			res?+=?iface.read（msgIn?4?len）;
		}
		return?res;
	}

	int?writeIBH（byte[]?buffer?int?len）?{
		iface.write（buffer?0?len）;
		if?（（Nodave.Debug?&?Nodave.DEBUG_IFACE）?!=?0）?{
			Nodave.dump（“writeIBH?“?buffer?0?len）;
		}
		return?0;
	}

	int?readIBHPacket（）?{
//		System.out.println（“readIBHPacket“）;
		int?i?res?=?0;
		res?=?iface.read（msgIn?0?3）;
//		System.out.println（“readIBHPacket??res:“?+?res）;
		if?（res?==?3）?{
			int?len?=?Nodave.USByte（msgIn?2）?+?5;
			res?+=?iface.read（msgIn?3?len）;
		}?else?{
			if?（（Nodave.Debug?&?Nodave.DEBUG_IFACE）?!=?0）?{
				System.out.println（“res?“?+?res）;
				Nodave.dump（“readIBHpacket:?short?packet“?msgIn?0?res）;
			}
			return?（0）;?//?short?packet
		}
		if?（（Nodave.Debug?&?Nodave.DEBUG_IFACE）?!=?0）?{

			System.out.println（
				“readIBHpacket:?“
					+?res
					+?“?bytes?read?“
					+?（msgIn[2]?+?8）
					+?“?needed“）;
			Nodave.dump（“readIBHpacket:?“?msgIn?0?res）;
		}
		return?（res）;
	};

	/*
		This?performs?initialization?steps?with?sampled?byte?sequences.?If?chal?is?<>NULL
		it?will?send?this?byte?sequence.
		It?will?then?wait?for?a?packet?and?compare?it?to?the?sample.
	*/
	int?initStepIBH（byte[]?chal?int[]?resp?int?rl）?{
		int?res?=?0?a?=?0;
		int?res2;
		if?（（Nodave.Debug?&?Nodave.DEBUG_CONNECT）?!=?0）
			System.out.println（“_daveInitStepIBH?before?write.\n“）;
		res?=?writeIBH（chal?chal.length）;
		if?（（Nodave.Debug?&?Nodave.DEBUG_CONNECT）?!=?0）
			System.out.println（“_daveInitStepIBH?write?returned?“?+?res）;
		//if?（res?		//	return?100;
		res?=?readIBHPacket（）;
		/*
			We?may?get?a?network?layer?ackknowledge?and?an?MPI?layer?ackknowledge?which?we?discard.
			So?normally?at?least?the?3rd?packet?should?h