Phase 3 PR 56 -- Siemens S7-1500 pymodbus profile + smoke integration test. Adds tests/ZB.MOM.WW.OtOpcUa.Driver.Modbus.IntegrationTests/Pymodbus/s7_1500.json modelling the SIMATIC S7-1500 + MB_SERVER default deployment documented in docs/v2/s7.md: DB1.DBW0 = 0xABCD fingerprint marker (operators reserve this so clients can verify they're talking to the right DB), scratch HR range 200..209 for write-roundtrip tests mirroring dl205.json + standard.json, Float32 1.5f at HR[100..101] in ABCD word order (high word first -- OPPOSITE of DL260 CDAB), Int32 0x12345678 at HR[300..301] in ABCD. Also seeds a coil at bit-addr 400 (= cell 25 bit 0) and a discrete input at bit-addr 500 (= cell 31 bit 0) so future S7-specific tests for FC01/FC02 have stable markers. shared blocks=true to match the proven dl205.json pattern (pymodbus's bits/uint16 cells coexist cleanly when addresses don't collide). Write list references cells (0, 25, 100-101, 200-209, 300-301), not bit addresses -- pymodbus's write-range entries are cell-indexed, not bit-indexed. Adds tests/ZB.MOM.WW.OtOpcUa.Driver.Modbus.IntegrationTests/S7/ directory with S7_1500Profile.cs (mirrors DL205Profile pattern: SmokeHoldingRegister=200, SmokeHoldingValue=4321, BuildOptions tags + probe-disabled + 2s timeout) and S7_1500SmokeTests.cs (single fact S7_1500_roundtrip_write_then_read_of_holding_register that writes SmokeHoldingValue then reads it back, asserting both write status 0 and read status 0 + value equality). Gates on MODBUS_SIM_PROFILE=s7_1500 so the test skips cleanly against other profiles. csproj updated to copy S7/** to test output as PreserveNewest (pattern matching DL205/**). Pymodbus/serve.ps1 ValidateSet extended from {standard,dl205} to {standard,dl205,s7_1500,mitsubishi} -- mitsubishi.json lands in PR 58 but the validator slot is claimed now so the serve.ps1 diff is one line in this PR and zero lines in future PRs. Verified end-to-end: smoke test 1/1 passes against the running pymodbus s7_1500 profile (localhost:5020 FC06 write of 4321 at HR[200] + FC03 read back). 143/143 Modbus.Tests pass, no regression in driver code because this PR is purely test-asset. Per-quirk S7 integration tests (ABCD word order default, FC23 IllegalFunction, MB_SERVER STATUS 0x8383 behaviour, port-per-connection semantics) land in PR 57+.

tests/ZB.MOM.WW.OtOpcUa.Driver.Modbus.IntegrationTests/S7/S7_1500Profile.cs

@@ -0,0 +1,44 @@
+namespace ZB.MOM.WW.OtOpcUa.Driver.Modbus.IntegrationTests.S7;
+
+/// <summary>
+///     Tag map for the Siemens SIMATIC S7-1500 device class with the <c>MB_SERVER</c> library
+///     block mapping HR[0..] to DB1.DBW0+. Mirrors <c>s7_1500.json</c> in <c>Pymodbus/</c>.
+/// </summary>
+/// <remarks>
+///     Unlike DL205, S7 has no fixed Modbus memory map — every site wires MB_SERVER to a
+///     different DB. The profile here models the *default* user layout documented in
+///     <c>docs/v2/s7.md</c> §per-model-matrix: DB1.DBW0 = fingerprint marker, a scratch HR
+///     range 200..209 for write-roundtrip tests, and ABCD-order Float32 / Int32 markers at
+///     HR[100..101] and HR[300..301] to prove the driver's S7 profile default is correct.
+/// </remarks>
+public static class S7_1500Profile
+{
+    /// <summary>
+    ///     Scratch HR the smoke test writes + reads. Address 200 mirrors the DL205 /
+    ///     standard scratch range so one smoke test pattern works across all device profiles.
+    /// </summary>
+    public const ushort SmokeHoldingRegister = 200;
+
+    /// <summary>Value the smoke test writes then reads back.</summary>
+    public const short SmokeHoldingValue = 4321;
+
+    public static ModbusDriverOptions BuildOptions(string host, int port) => new()
+    {
+        Host = host,
+        Port = port,
+        UnitId = 1,
+        Timeout = TimeSpan.FromSeconds(2),
+        Tags =
+        [
+            new ModbusTagDefinition(
+                Name: "Smoke_HReg200",
+                Region: ModbusRegion.HoldingRegisters,
+                Address: SmokeHoldingRegister,
+                DataType: ModbusDataType.Int16,
+                Writable: true),
+        ],
+        // Disable the background probe loop — integration tests drive reads explicitly and
+        // the probe would race with assertions.
+        Probe = new ModbusProbeOptions { Enabled = false },
+    };
+}