Recent changes to bugs

Bug in libnodave-java which limits readable bytes to just 102

Ralf Kern — Fri, 18 Mar 2016 12:24:37 -0000

There is a bug in libnodave-java, which only allows to get 102 Bytes per read.
In TCPConnection please change readIsoPacket() to:

    protected int readISOPacket() {
        int res = iface.read(msgIn, 0, 4);
        if (res == 4) {
            //int len = 0x100 * msgIn[2] + msgIn[3]; --> wrong code
            int len = 0x100 *(msgIn[2] & 0xFF) + (msgIn[3] & 0xFF)
            res += iface.read(msgIn, 4, len);
        } else return 0;
        return res;
    }

In Java all Bytes are signed, but you were assuming an unsigned Byte here.
With this error you will only get 127 Bytes at max - minus header of 25 Bytes, you are getting only 102 Bytes at max.

CSharp daveSwapIed_16 incorrect marshalling

Nicola Dell'Amico — Fri, 19 Jun 2015 16:05:52 -0000

The dotnet wrapper daveSwapIed_16 seems to be incorrect and returns undefined results:
[DllImport("libnodave.dll"/, PreserveSig=false / )]
public static extern int daveSwapIed_16(int i);
The input and return type should be short:
[DllImport("libnodave.dll"/, PreserveSig=false / )]
public static extern short daveSwapIed_16(short i);

Recompiled the wrapper and tested seems to work correctly

daveGetBlockInfo doesn't work for all blocks

Benjamin Prömmer — Tue, 31 Mar 2015 06:18:33 -0000

For some blocks daveBuildAndSendPDU returns data with a DataLength of 96 (normaly the blocks have a DataLength of 82), and because of this check

                        "p2.udlen==sizeof(daveBlockInfo)"

daveGetBlockInfo Returns res==0 but without any data in the blockInfo struct. I think it's better if you check like this

                         "p2.udlen>=sizeof(daveBlockInfo)"

and copy then only sizeof(daveBlockInfo) to the blockinfo struct.

Unfortunately, I do not know what is included in the additional Bytes. In my tests the bytes are always empty (as 0x00).

Best reagds,
Benji

Doonread is called twice under different contexes in unit NoDaveComponent.pas for Delphi, Lazarus

Christian — Tue, 06 May 2014 08:11:43 -0000

Hi,

when using several connection the values were mixed. To solve this problem i found the following solution:

The Funtion DoOnread is called in TNodave.Readbytes and in TNoDaveReadThread.Execute.
TNoDaveReadThread.Execute however calls TNodave.Readbyte too so DoOnread is called twice.
One call is in the cantext of the thread the other is Synchronized.
So the values to be worked with can come from other connections.

procedure TNoDave.ReadBytes(Buffer: Pointer);
begin
If not Assigned(Buffer) then Buffer:=FBuffer;
If Active then
begin
DoReadBytes(FArea, FDBNumber, FBufOffs, FBufLen, Buffer);
//DoOnRead; <- commending out solves the problem
end;
end;

procedure TNoDaveReadThread.Execute;
var
StartTime: Cardinal;
NextTime: Cardinal;
begin
While NoDave.Active and (NoDave.Interval > 0) do
begin
StartTime:=GetTickCount;
NextTime:=StartTime + NoDave.Interval;
try
NoDave.ReadBytes; // read in context of thread
If NoDave.LastError = 0
then Synchronize(DoOnRead) // read in context of main thread
else
....

I use Lazarus 1.0.13 with FPC 2.6.2 in Windows 7
and hope this helps.

Christian

problem with daveReadSZL in case of timeout

Markus Strehlau — Tue, 14 May 2013 09:05:55 -0000

In function daveReadSZL, after the call of daveBuildAndSendPDU the returned PDU p2 is used, even if an error like a timeout occured and p2 is not initialized.

Original code beginning at line 1127 in nodave.c

    res=daveBuildAndSendPDU(dc, &p2,pa, sizeof(pa), da, sizeof(da));

    len=0;
    pa7=p2.param[7];
//    pa6=p2.param[6];
    while (p2.param[9]!=0) {
    ....

Better would be

    res=daveBuildAndSendPDU(dc, &p2,pa, sizeof(pa), da, sizeof(da));
    if (res!=daveResOK) 
        return res;

    len=0;
    pa7=p2.param[7];
//    pa6=p2.param[6];
    while (p2.param[9]!=0) {
    ....

At least, there are some more functions which have a problem if daveBuildAndSendPDU gets an error, like daveGetBlockInfo, daveListBlocks

Assigning wrong rack number on isoTCP

vita — Tue, 04 Sep 2012 14:26:52 -0000

Hi. In source file nodave.c (version 0.8.4.6) on line 4025 is wrong assigning CPU rack number.
Originally was in there:

dc->msgOut[17]=dc->rack+1;
dc->msgOut[18]=dc->slot;

and it should be:

dc->msgOut[18]= dc->slot | (dc->rack << 5);

Byte with Rack/Slot definition: bit 0..4 Slot; bit 5..7 Rack

Memory Leak in openSocketw.c

Klaus Albert — Sat, 04 Dec 2010 22:54:10 -0000

There is a memory leak due to not calling WSACleanup().
Fixed lines in openSocketw.c is supplied below:

.....
if (connect(fd, (struct sockaddr *) & addr, addrlen)) {
if (daveDebug & daveDebugOpen) {
LOG2(ThisModule "connect Socket error: %s \n", strerror(errno));
}
// socketClose(fd);
closesocket(fd);
WSACleanup(); // FIXED MEMORY LEAK
fd = 0;
} else {
....

and
......
__declspec (dllexport) int __stdcall closeSocket(SOCKET h) {
closesocket(h);
WSACleanup(); // FIXED MEMORY LEAK

return 0;
}
....

SetPLCTimeS has problems with the year 2010

klaly — Tue, 05 Jan 2010 12:11:03 -0000

If you try to set the PC-systemtime with the function SetPLCTimeS, all was fine in year 2000 ... 2009.
But now in 2010, the date will be setted to 2000, it seems to be a problem with modulo division.

If i can find a solution, than i will pos it.

libnodave java PLCinterface swallows IOExceptions

polac — Thu, 11 Jun 2009 10:46:42 -0000

PLCinterface classes write- and read-methods both swallows IOExceptions. Would it be more helpfull for the application writer if libnodave library reports when the underlying connection is not valid anymore.

function toPLCfloat

Anonymous — Fri, 18 Jul 2008 05:28:37 -0000

The function toPLCfloat does no byte swapping even if DAVE_LITTLE_ENDIAN is defined.
This is caused by the following line in this function:
f.a=ff;
After removing this line, the function works well.