phase 2 serial

tools/modbus_scanner.cpp

@@ -0,0 +1,27 @@
+#include <iostream>
+#include <string>
+
+int main(int argc, char* argv[])
+{
+    std::string port = "/dev/ttyUSB0";
+    int baud = 9600;
+    int slaveStart = 1;
+    int slaveEnd = 10;
+    for (int i = 1; i < argc; ++i) {
+        const std::string arg = argv[i];
+        if (arg == "--port" && i + 1 < argc) {
+            port = argv[++i];
+        } else if (arg == "--baud" && i + 1 < argc) {
+            baud = std::stoi(argv[++i]);
+        } else if (arg == "--slave-start" && i + 1 < argc) {
+            slaveStart = std::stoi(argv[++i]);
+        } else if (arg == "--slave-end" && i + 1 < argc) {
+            slaveEnd = std::stoi(argv[++i]);
+        }
+    }
+    std::cout << "modbus_scanner: draft output for physical_devices.json\n";
+    std::cout << "  port=" << port << " baud=" << baud
+              << " slaves=" << slaveStart << "-" << slaveEnd << "\n";
+    std::cout << "  Run with libmodbus integration to probe registers (Phase 2 tool).\n";
+    return 0;
+}