1. Added support for connecting to PLCs when "Only secure PG/PC and HMI communication" option is enabled

2. Fixed connection failure errors when PLC has "Only secure PG/PC and HMI communication" enabled

3. Fixed null reference errors when SessionKey is empty due to connection failures

DriverTest/Program.cs

@@ -1,4 +1,6 @@
-
+//#define _TEST_BASIC_VAR
+#define _TEST_PLCTAG
+
 using System;
 using System.Collections.Generic;
 using System.IO;
@@ -15,7 +17,7 @@ namespace DriverTest
     {
         static void Main(string[] args)
         {
-            string HostIp = "192.168.0.250";
+            string HostIp = "192.168.0.1";
             string Password = "";
             int res;
             List<ItemAddress> readlist = new List<ItemAddress>();
@@ -31,9 +33,17 @@ namespace DriverTest
             Console.WriteLine("Main - Versuche Verbindungsaufbau zu: " + HostIp);
 
             S7CommPlusConnection conn = new S7CommPlusConnection();
+            conn.OnlySecurePGOrPCAndHMI = true;//Only secure PG/PC and HMI communication
+            System.Diagnostics.Stopwatch stopwatch1 = new System.Diagnostics.Stopwatch();
+            stopwatch1.Start();
             res = conn.Connect(HostIp, Password);
+            stopwatch1.Stop();
+            Console.WriteLine($"PLCType: {conn.PLCInformation.PLCType} | MLFB: {conn.PLCInformation.MLFB} | Firmware: {conn.PLCInformation.Firmware}");
+            Console.WriteLine($"连接耗时{stopwatch1.ElapsedMilliseconds}ms.");
             if (res == 0)
             {
+                Console.WriteLine("按任意键浏览变量");
+                Console.ReadKey();
                 Console.WriteLine("Main - Connect fertig");
 
                 #region Variablenhaushalt browsen
@@ -43,7 +53,8 @@ namespace DriverTest
                 res = conn.Browse(out vars);
                 Console.WriteLine("Main - Browse res=" + res);
                 #endregion
-                List<VarInfo> vars_ = vars.GetRange(0,1000);
+                List<VarInfo> vars_ = vars.GetRange(0,50);
+#if _TEST_PLCTAG
                 #region Werte aller Variablen einlesen
                 Console.WriteLine("Main - Lese Werte aller Variablen aus");
 
@@ -77,18 +88,20 @@ namespace DriverTest
                 Console.ReadKey();
                 while (res == 0)
                 {
-                    System.Diagnostics.Stopwatch stopwatch = new System.Diagnostics.Stopwatch();
-                    stopwatch.Start();
+                    System.Diagnostics.Stopwatch stopwatch2 = new System.Diagnostics.Stopwatch();
+                    stopwatch2.Start();
                     res = tags.ReadTags(conn);
-                    stopwatch.Stop();
-                    long ms = stopwatch.ElapsedMilliseconds;
+                    stopwatch2.Stop();
+                    long ms = stopwatch2.ElapsedMilliseconds;
                     if (res == 0)
                     {
                         string header = $"读取{vars_.Count}个变量耗时{ms}毫秒";
                         Console.WriteLine(header);
                     }
                 }
-                
+#endif
+
+#if _TEST_BASIC_VAR
                 #region Werte aller Variablen einlesen
                 Console.WriteLine("Main - Lese Werte aller Variablen aus");
 
@@ -123,6 +136,7 @@ namespace DriverTest
                     Console.WriteLine("===============================================================");
                 }
                 #endregion
+#endif
 
                 /*
                 #region Test: Wert schreiben

DriverTest/bin/Debug/key_20251031_150257.log

@@ -0,0 +1,5 @@
+SERVER_HANDSHAKE_TRAFFIC_SECRET 9d2884bb6d1ca343e259a23ffd195961228283a253916cb75661a90dbfa056f0 54afed328765987b013f17d3425b5ad139cd775ded5d8e9bd12fa96f93166508f793dca53267752de04c627218b51e4c
+EXPORTER_SECRET 9d2884bb6d1ca343e259a23ffd195961228283a253916cb75661a90dbfa056f0 eaa6ef9882ce9d8c002ab41043f699f94d2a34fae101b9a2cd773dfdf7e6329acb65f2f6301c6894331bb62c35a63429
+SERVER_TRAFFIC_SECRET_0 9d2884bb6d1ca343e259a23ffd195961228283a253916cb75661a90dbfa056f0 87149d68005b5512c6efbce24dcfb35146a4c49dcc2cc29d84294c566a45ee66b53df30eafea7c3f4070df9959d7f6be
+CLIENT_HANDSHAKE_TRAFFIC_SECRET 9d2884bb6d1ca343e259a23ffd195961228283a253916cb75661a90dbfa056f0 d1d792a9d1a2f49dbda3f09b48a25de60192cef4434efd5cf51a61f73ce9e6d7c4f4dc466a6694a6d5612efd2773f784
+CLIENT_TRAFFIC_SECRET_0 9d2884bb6d1ca343e259a23ffd195961228283a253916cb75661a90dbfa056f0 2238f875c69a7f5704c1792f3dec81b98af34d18643b467cccb730efc123c789632303c6e2c48dd2a397652ddfcf890a

DriverTest/bin/Debug/key_20251031_150910.log

@@ -0,0 +1,5 @@
+SERVER_HANDSHAKE_TRAFFIC_SECRET ef29f3273eb4c3848fb8e869418198253bb70d55e234e55ed14bf4b4bab5c5b4 5c61d992793df1e85a7f6d9c3ffd27084373954871a262ccd827c65dc9a10b0fb8153392ced7cacdcb5c523d5eac9adb
+EXPORTER_SECRET ef29f3273eb4c3848fb8e869418198253bb70d55e234e55ed14bf4b4bab5c5b4 97ed8911dac9e9e8543496c3ebf120a804da5fa88f70854e693a83db5b9f39d45a7c223f2782c6fc6943f18916c797f7
+SERVER_TRAFFIC_SECRET_0 ef29f3273eb4c3848fb8e869418198253bb70d55e234e55ed14bf4b4bab5c5b4 3ca5d277257f1f536affba73730ec5561eb3654eddb53146e3935f79f3dde5d9b11220936506aa7c2806ba0fd3df065c
+CLIENT_HANDSHAKE_TRAFFIC_SECRET ef29f3273eb4c3848fb8e869418198253bb70d55e234e55ed14bf4b4bab5c5b4 caf02ef79a590b2d9dd78149774174c4a305bc9255fb1df90c66f61e9445be5d74c43b2eff8be2aebfab27ca40751d3c
+CLIENT_TRAFFIC_SECRET_0 ef29f3273eb4c3848fb8e869418198253bb70d55e234e55ed14bf4b4bab5c5b4 9d6d6cc9fc091479726907304d7c47d84e718db4b09319871d009dc7eb19c5795487528194c362708cd86faf4452f73b

DriverTest/obj/Debug/DriverTest.csproj.CoreCompileInputs.cache

@@ -0,0 +1 @@
+dc7d04987a3dea6ec27cb7cd218eb8ff538ad9f0

DriverTest/obj/Debug/DriverTest.csproj.FileListAbsolute.txt

@@ -0,0 +1,14 @@
+C:\Users\ShenX\Desktop\DiscoverDevices\S7CommPlusV3Driver\DriverTest\obj\Debug\DriverTest.csproj.CoreCompileInputs.cache
+C:\Users\ShenX\Desktop\DiscoverDevices\S7CommPlusV3Driver\DriverTest\bin\Debug\DriverTest.exe.config
+C:\Users\ShenX\Desktop\DiscoverDevices\S7CommPlusV3Driver\DriverTest\bin\Debug\DriverTest.exe
+C:\Users\ShenX\Desktop\DiscoverDevices\S7CommPlusV3Driver\DriverTest\bin\Debug\DriverTest.pdb
+C:\Users\ShenX\Desktop\DiscoverDevices\S7CommPlusV3Driver\DriverTest\bin\Debug\S7CommPlusDriver.dll
+C:\Users\ShenX\Desktop\DiscoverDevices\S7CommPlusV3Driver\DriverTest\bin\Debug\S7PublicKeys.dll
+C:\Users\ShenX\Desktop\DiscoverDevices\S7CommPlusV3Driver\DriverTest\bin\Debug\S7Utilities.dll
+C:\Users\ShenX\Desktop\DiscoverDevices\S7CommPlusV3Driver\DriverTest\bin\Debug\zlib.net.dll
+C:\Users\ShenX\Desktop\DiscoverDevices\S7CommPlusV3Driver\DriverTest\bin\Debug\S7CommPlusAuth.dll
+C:\Users\ShenX\Desktop\DiscoverDevices\S7CommPlusV3Driver\DriverTest\bin\Debug\S7Family0.dll
+C:\Users\ShenX\Desktop\DiscoverDevices\S7CommPlusV3Driver\DriverTest\obj\Debug\DriverTest.csproj.CopyComplete
+C:\Users\ShenX\Desktop\DiscoverDevices\S7CommPlusV3Driver\DriverTest\obj\Debug\DriverTest.exe
+C:\Users\ShenX\Desktop\DiscoverDevices\S7CommPlusV3Driver\DriverTest\obj\Debug\DriverTest.pdb
+C:\Users\ShenX\Desktop\DiscoverDevices\S7CommPlusV3Driver\DriverTest\obj\Debug\DriverTest.csprojAssemblyReference.cache

S7CommPlusGUIBrowser/obj/Debug/S7CommPlusGUIBrowser.csproj.CoreCompileInputs.cache

@@ -0,0 +1 @@
+ec14fa67cfbca0656c6c62f93ec1446787c52f00

S7CommPlusGUIBrowser/obj/Debug/S7CommPlusGUIBrowser.csproj.FileListAbsolute.txt

@@ -0,0 +1,17 @@
+C:\Users\ShenX\Desktop\DiscoverDevices\S7CommPlusV3Driver\S7CommPlusGUIBrowser\bin\Debug\S7CommPlusGUIBrowser.exe.config
+C:\Users\ShenX\Desktop\DiscoverDevices\S7CommPlusV3Driver\S7CommPlusGUIBrowser\bin\Debug\S7CommPlusGUIBrowser.exe
+C:\Users\ShenX\Desktop\DiscoverDevices\S7CommPlusV3Driver\S7CommPlusGUIBrowser\bin\Debug\S7CommPlusGUIBrowser.pdb
+C:\Users\ShenX\Desktop\DiscoverDevices\S7CommPlusV3Driver\S7CommPlusGUIBrowser\bin\Debug\S7CommPlusDriver.dll
+C:\Users\ShenX\Desktop\DiscoverDevices\S7CommPlusV3Driver\S7CommPlusGUIBrowser\obj\Debug\S7CommPlusGUIBrowser.csprojAssemblyReference.cache
+C:\Users\ShenX\Desktop\DiscoverDevices\S7CommPlusV3Driver\S7CommPlusGUIBrowser\obj\Debug\S7CommPlusGUIBrowser.Form1.resources
+C:\Users\ShenX\Desktop\DiscoverDevices\S7CommPlusV3Driver\S7CommPlusGUIBrowser\obj\Debug\S7CommPlusGUIBrowser.Properties.Resources.resources
+C:\Users\ShenX\Desktop\DiscoverDevices\S7CommPlusV3Driver\S7CommPlusGUIBrowser\obj\Debug\S7CommPlusGUIBrowser.csproj.GenerateResource.cache
+C:\Users\ShenX\Desktop\DiscoverDevices\S7CommPlusV3Driver\S7CommPlusGUIBrowser\obj\Debug\S7CommPlusGUIBrowser.csproj.CoreCompileInputs.cache
+C:\Users\ShenX\Desktop\DiscoverDevices\S7CommPlusV3Driver\S7CommPlusGUIBrowser\obj\Debug\S7CommPlusGUIBrowser.csproj.CopyComplete
+C:\Users\ShenX\Desktop\DiscoverDevices\S7CommPlusV3Driver\S7CommPlusGUIBrowser\obj\Debug\S7CommPlusGUIBrowser.exe
+C:\Users\ShenX\Desktop\DiscoverDevices\S7CommPlusV3Driver\S7CommPlusGUIBrowser\obj\Debug\S7CommPlusGUIBrowser.pdb
+C:\Users\ShenX\Desktop\DiscoverDevices\S7CommPlusV3Driver\S7CommPlusGUIBrowser\bin\Debug\S7PublicKeys.dll
+C:\Users\ShenX\Desktop\DiscoverDevices\S7CommPlusV3Driver\S7CommPlusGUIBrowser\bin\Debug\S7Utilities.dll
+C:\Users\ShenX\Desktop\DiscoverDevices\S7CommPlusV3Driver\S7CommPlusGUIBrowser\bin\Debug\zlib.net.dll
+C:\Users\ShenX\Desktop\DiscoverDevices\S7CommPlusV3Driver\S7CommPlusGUIBrowser\bin\Debug\S7CommPlusAuth.dll
+C:\Users\ShenX\Desktop\DiscoverDevices\S7CommPlusV3Driver\S7CommPlusGUIBrowser\bin\Debug\S7Family0.dll