Get CPU ordernumber (MLFB) from CPUFolders.

Attempt at reading out the MLFB from *.s7h files in the "s7hstatx" folder.

The byte sequence that define the position of the MLFB string in the file
appear to be different among PLC types, thus the different seqeuences
are all tested against. However, there may be more sequences that should
be added, but it must be tested with more Step7 projects. Currently tested
with 7 different CPU types.

Probably there is another way to identify the location of the MLFB string
that is more deterministic than this pragmatic method. Hopefully someone
will find that way.

Another weakness with this method is that for one out of 35 projects tested,
the s7h file did not exist. Only after a HWConfig recompile was it created.
Maybe it was last compiled by on old Step7 version, or there have been
an error of some kind.

LibNoDaveConnectionLibrary/DataTypes/Projectfolders/Step7V5/CPUFolder.cs

@@ -12,6 +12,8 @@ public class CPUFolder : Step7ProjectFolder, IHardwareFolder
         internal int TobjId;
         public PLCType CpuType { get; set; }
 
+        public string MLFB_OrderNumber { get; set; }
+
         public string PasswdHard { get; set; }
 
         public int Rack { get; set; }

LibNoDaveConnectionLibrary/Projectfiles/Step7ProjectV5.cs

@@ -506,6 +506,63 @@ override protected void LoadProject()
                 }
             }
 
+            //Get The CPU Order number (MLFB)
+            foreach (var y in CPUFolders)
+            {
+                string filepath = ProjectFolder + "hOmSave7" + _DirSeperator + 
+                    "s7hstatx" + _DirSeperator + y.UnitID.ToString("x") + ".s7h";
+                if (!_ziphelper.FileExists(filepath))
+                    continue; //In some projects the s7h files does not exist, but is created after a HWconf recompile (v5.6 SP1 HF5).
+
+                Stream s7h = _ziphelper.GetReadStream(filepath);
+                BinaryReader rd = new BinaryReader(s7h);
+                byte[] completeBuffer = rd.ReadBytes((int)_ziphelper.GetStreamLength(filepath, s7h));
+                rd.Close();
+                s7h.Close();
+
+                // Byte sequence before information about each slot on the rack.
+                string[] checkSequences = {
+                    ASCIIEncoding.ASCII.GetString(new byte[] { 0x0a, 0x00, 0x03 }),// 319-3 (EL00/01), 317-2DP
+                    ASCIIEncoding.ASCII.GetString(new byte[] { 0x0c, 0x00, 0x03 }),// 317T-3 PN/DP
+                    ASCIIEncoding.ASCII.GetString(new byte[] { 0x09, 0x00, 0x03 }) // PLCType.SimaticRTX
+                };
+                string buffer = ASCIIEncoding.ASCII.GetString(completeBuffer);
+                List<IEnumerable<int>> hitsList = new List<IEnumerable<int>>();
+                foreach ( string checkSeq in checkSequences)
+                {
+                    //Find the indexes of the matches in the byte-buffer.
+                    var matches = System.Text.RegularExpressions.Regex.
+                        Matches(buffer, checkSeq).Cast<System.Text.
+                        RegularExpressions.Match>().Select(m => m.Index);
+                    // If the byte address i higher than 2000, it is most likely
+                    // not the CPU MLFB that is found.
+                    if (matches.Count() > 0 && matches.ElementAt(0) < 2000)
+                    {
+                        hitsList.Add(matches);
+                    }                    
+                }
+                // Sort the list by the result with most matches. 
+                hitsList.Sort((a,b) => b.Count() - a.Count());
+                // Take the result with the most matches.
+                IEnumerable<int> matchList = hitsList.First();
+
+                // The first hit has e.g. slot1, power supply etc.
+                // The second hit has the CPU information
+                if (matchList.Count() < 2)
+                    continue;      
+
+                //The length of the text field is the byte before the text field.
+                //First two fields are seperated by bytes "03 20 20 32"
+                int descrStart = matchList.ElementAt(1);                
+                int dscr1_length = completeBuffer[descrStart + 6]; // CPU Name
+                int dscr2_length = completeBuffer[descrStart + 6 + dscr1_length + 5]; // CPU Name
+                int dscr3_length = completeBuffer[descrStart + 6 + dscr1_length + 5 + dscr2_length + 1]; // CPU MLFB
+                int dscr3_position = descrStart + 6 + dscr1_length + 5 + dscr2_length + 2;
+                string descr3 = ASCIIEncoding.ASCII.GetString(completeBuffer, dscr3_position, dscr3_length);
+
+                y.MLFB_OrderNumber = descr3;                                    
+            }
+
             //Get The CPU(ET200S)...
             if (_ziphelper.FileExists(ProjectFolder + "hOmSave7" + _DirSeperator + "s7hkcomx" + _DirSeperator + "HOBJECT1.DBF"))
             {