Docs + code-comment sweep — remove stale Pymodbus/ + PythonSnap7/ + LocateBinary references left behind by the native-fallback removal PR. Answer to "is the dev inventory + documentation updated": it was partial; this PR finishes the job.

Files touched — docs/drivers/Modbus-Test-Fixture.md dropped the key-files pointer at deleted Pymodbus/ + flipped "primary launcher is Docker, native fallback retained" framing to "Docker is the only supported launch path" (matching the code). docs/v2/dev-environment.md dropped the "skips both Docker + native-binary paths" parenthetical from AB_SERVER_ENDPOINT + flipped the "Native fallbacks" subsection to a one-liner that says Docker is the only supported path. docs/v2/modbus-test-plan.md rewrote §Harness from "pip install pymodbus + serve.ps1" setup pattern to "docker compose --profile <…> up" + updated the §PR 43 status bullet to point at Docker/profiles/. docs/v2/test-data-sources.md §"CI fixture (task #180)" rewrote the AB CIP section from "LocateBinary() picks binary off PATH" + GitHub Actions zip-download step to "Docker is the only supported reproducible build path" + docker compose GitHub Actions step; dropped the pinned-version SHA256 table + lock-file reference because the Dockerfile's LIBPLCTAG_TAG build-arg is the new pin.

Code docstrings + error messages — these are developer-facing operational text too. ModbusSimulatorFixture SkipReason strings (both branches) now point at `docker compose -f Docker/docker-compose.yml --profile standard up -d` instead of the deleted `Pymodbus\serve.ps1`; doc-comment at the top references Docker/docker-compose.yml. Snap7ServerFixture SkipReason strings + doc-comment point at Docker/docker-compose.yml instead of PythonSnap7/serve.ps1. S7_1500Profile.cs docstring updated. Modbus Dockerfile comment pointing at deleted tests/.../Pymodbus/README.md redirected to docs/drivers/Modbus-Test-Fixture.md. DL205Profile.cs + DL205StringQuirkTests.cs + S7_1500Profile.cs (in Modbus project) docstrings flipped from Pymodbus/*.json references to Docker/profiles/*.json.

Left untouched deliberately: docs/v2/implementation/exit-gate-phase-2-closed.md — that's a historical as-of-2026-04-18 snapshot documenting what was skipped at Phase 2 closure; rewriting would lose the date-stamped context. Its "oitc/modbus-server Docker container not started" + "ab_server binary not on PATH" lines describe the fixture landscape that existed at close time, not current operational guidance.

Final sweep confirms zero remaining `Pymodbus/` / `PythonSnap7/` / `LocateBinary` / `AbServerSeedTag` / `BuildCliArgs` / `AbServerPlcArg` mentions anywhere in tracked files outside that historical exit-gate doc. Whole-solution build still 0 errors.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

docs/drivers/Modbus-Test-Fixture.md

@@ -113,5 +113,5 @@ Not a Modbus concept. Driver doesn't implement `IAlarmSource` or
 - `tests/ZB.MOM.WW.OtOpcUa.Driver.Modbus.IntegrationTests/DL205/DL205Profile.cs`
 - `tests/ZB.MOM.WW.OtOpcUa.Driver.Modbus.IntegrationTests/Mitsubishi/MitsubishiProfile.cs`
 - `tests/ZB.MOM.WW.OtOpcUa.Driver.Modbus.IntegrationTests/S7/S7_1500Profile.cs`
-- `tests/ZB.MOM.WW.OtOpcUa.Driver.Modbus.IntegrationTests/Pymodbus/` — simulator
-  driver script + per-family JSON profiles
+- `tests/ZB.MOM.WW.OtOpcUa.Driver.Modbus.IntegrationTests/Docker/` —
+  Dockerfile + compose + per-family JSON profiles

docs/v2/dev-environment.md

@@ -174,7 +174,7 @@ libplctag + compiles C). Stop with `docker compose -f <compose> --profile <…>
 real PLC instead of the simulator:
 
 - `MODBUS_SIM_ENDPOINT` (default `localhost:5020`)
-- `AB_SERVER_ENDPOINT` (no default; when set, skips both Docker + native-binary paths)
+- `AB_SERVER_ENDPOINT` (no default; overrides the local container endpoint)
 - `S7_SIM_ENDPOINT` (default `localhost:1102`)
 - `OPCUA_SIM_ENDPOINT` (default `opc.tcp://localhost:50000`)
 

docs/v2/modbus-test-plan.md

@@ -13,9 +13,9 @@ confirmed DL205 quirk lands in a follow-up PR as a named test in that project.
 
 ## Harness
 
-**Chosen simulator: pymodbus 3.13.0** (`pip install 'pymodbus[simulator]==3.13.0'`).
-Replaced ModbusPal in PR 43 — see `tests/.../Pymodbus/README.md` for the
-trade-off rationale. Headline reasons:
+**Chosen simulator: pymodbus 3.13.0** packaged as a pinned Docker image
+under `tests/.../Modbus.IntegrationTests/Docker/`. See that folder's
+`README.md` for image-build notes + compose profiles. Headline reasons:
 
 - **Headless** pure-Python CLI; no Java GUI, runs cleanly on a CI runner.
 - **Maintained** — current stable 3.13.0; ModbusPal 1.6b is abandoned.
@@ -26,17 +26,18 @@ trade-off rationale. Headline reasons:
 - **Per-register raw uint16 seeding** — encoding the DL205 string-byte-order
   / BCD / CDAB-float quirks stays explicit (the quirk math lives in the
   `_quirk` JSON-comment fields next to each register).
-- Pip-installable on Windows; sidesteps the privileged-port admin
-  requirement by defaulting to TCP **5020** instead of 502.
+- **Dockerized** — pinned image means the CI simulator surface is
+  reproducible + no `pip install` step on the dev box.
+- Defaults to TCP **5020** (matches the compose port-map + the fixture
+  default endpoint; sidesteps the Windows Firewall prompt on 502).
 
 **Setup pattern**:
-1. `pip install "pymodbus[simulator]==3.13.0"`.
-2. Start the simulator with one of the in-repo profiles:
-   `tests\.../Pymodbus\serve.ps1 -Profile standard` (or `-Profile dl205`).
-3. `dotnet test tests\ZB.MOM.WW.OtOpcUa.Driver.Modbus.IntegrationTests` —
+1. `docker compose -f tests\...\Modbus.IntegrationTests\Docker\docker-compose.yml --profile <standard|dl205|mitsubishi|s7_1500> up -d`.
+2. `dotnet test tests\ZB.MOM.WW.OtOpcUa.Driver.Modbus.IntegrationTests` —
    tests auto-skip when the endpoint is unreachable. Default endpoint is
    `localhost:5020`; override via `MODBUS_SIM_ENDPOINT` for a real PLC on its
    native port 502.
+3. `docker compose -f ... --profile <…> down` when finished.
 
 ## Per-device quirk catalog
 
@@ -113,9 +114,11 @@ vendors get promoted into driver defaults or opt-in options:
 - **PR 42 — ModbusPal `.xmpp` profiles** — **SUPERSEDED by PR 43**. Replaced
   with pymodbus JSON because ModbusPal 1.6b is abandoned, GUI-only, and only
   exposes 2 of the 4 standard tables.
-- **PR 43 — pymodbus JSON profiles** — **DONE**. `Pymodbus/standard.json` +
-  `Pymodbus/dl205.json` + `Pymodbus/serve.ps1` runner. Both bind TCP 5020.
+- **PR 43 — pymodbus JSON profiles** — **DONE**. Dockerized under
+  `Docker/profiles/` (standard.json, dl205.json, mitsubishi.json,
+  s7_1500.json); compose file launches each via a named profile.
+  All bind TCP 5020.
 - **PR 44+**: one PR per confirmed DL205 quirk, landing the named test + any
   driver-side adjustment (string byte order, BCD decoder, V-memory address
   helper, FC16 cap-per-device-family) needed to pass it. Each quirk's value
-  is already pre-encoded in `Pymodbus/dl205.json`.
+  is already pre-encoded in `Docker/profiles/dl205.json`.

docs/v2/test-data-sources.md

@@ -191,40 +191,30 @@ Modbus has no native String, DateTime, or Int64 — those rows are skipped on th
 
 ### CI fixture (task #180)
 
-The integration harness at `tests/ZB.MOM.WW.OtOpcUa.Driver.AbCip.IntegrationTests/` exposes two test-time contracts:
+The integration harness at `tests/ZB.MOM.WW.OtOpcUa.Driver.AbCip.IntegrationTests/` is Docker-only — `ab_server` is a source-only tool under libplctag's `src/tools/ab_server/`, and the fixture's multi-stage `Docker/Dockerfile` is the only supported reproducible build path.
 
-- **`AbServerFixture(AbServerProfile)`** — starts the simulator with the CLI args composed from the profile's `--plc` family + seed-tag set. One fixture instance per family, one simulator process per test case (smoke tier). For larger suites that can share a simulator across several reads/writes, use a `IClassFixture<AbServerFixture>` wrapper per family.
-- **`KnownProfiles.{ControlLogix, CompactLogix, Micro800, GuardLogix}`** — the four per-family profiles. Drives the simulator's `--plc` mode + the preseed `--tag name:type[:size]` set. Micro800 + GuardLogix fall back to `controllogix` under the hood because ab_server has no dedicated mode for them — the driver-side family profile still enforces the narrower connection shape / safety classification separately.
+- **`AbServerFixture(AbServerProfile)`** — thin TCP probe against `127.0.0.1:44818` (or `AB_SERVER_ENDPOINT` override). Does not spawn the simulator; the operator brings up the compose service for whichever family the test class targets (`controllogix` / `compactlogix` / `micro800` / `guardlogix`).
+- **`KnownProfiles.{ControlLogix, CompactLogix, Micro800, GuardLogix}`** — thin `(Family, ComposeProfile, Notes)` records. The compose file (`Docker/docker-compose.yml`) is the canonical source of truth for which tags each family seeds + which `--plc` mode the simulator boots in. `Micro800` uses the dedicated `--plc=Micro800` mode; `GuardLogix` uses `ControlLogix` emulation because ab_server has no safety subsystem (the `_S`-suffixed seed tag triggers driver-side ViewOnly classification only).
 
-**Pinned version** (recorded in `ci/ab-server.lock.json` so drift is one-file visible):
-
-- `libplctag` **v2.6.16** (published 2026-03-29) — `ab_server.exe` ships inside the `_tools.zip` asset alongside `plctag.dll` + two `list_tags_*` helpers.
-- Windows x64: `libplctag_2.6.16_windows_x64_tools.zip` — SHA256 `9b78a3dee73d9cd28ca348c090f453dbe3ad9d07ad6bf42865a9dc3a79bc2232`
-- Windows x86: `libplctag_2.6.16_windows_x86_tools.zip` — SHA256 `fdfefd58b266c5da9a1ded1a430985e609289c9e67be2544da7513b668761edf`
-- Windows ARM64: `libplctag_2.6.16_windows_arm64_tools.zip` — SHA256 `d747728e4c4958bb63b4ac23e1c820c4452e4778dfd7d58f8a0aecd5402d4944`
+**Pinned version**: the `Docker/Dockerfile` clones libplctag at a pinned tag (currently the `release` branch) via its `LIBPLCTAG_TAG` build-arg and compiles `ab_server` from source. Bump deliberately alongside a driver-side change that needs the newer simulator.
 
 **CI step:**
 
 ```yaml
 # GitHub Actions step placed before `dotnet test`:
-- name: Fetch ab_server (libplctag v2.6.16)
+- name: Start ab_server Docker container
   shell: pwsh
   run: |
-    $pin = Get-Content ci/ab-server.lock.json | ConvertFrom-Json
-    $asset = $pin.assets.'windows-x64'       # swap to windows-x86 / windows-arm64 on non-x64 runners
-    $url = "https://github.com/libplctag/libplctag/releases/download/$($pin.tag)/$($asset.file)"
-    $zip = Join-Path $env:RUNNER_TEMP 'libplctag-tools.zip'
-    Invoke-WebRequest $url -OutFile $zip
-    $actual = (Get-FileHash -Algorithm SHA256 $zip).Hash.ToLower()
-    if ($actual -ne $asset.sha256) { throw "libplctag tools SHA256 mismatch: expected $($asset.sha256), got $actual" }
-    $dest = Join-Path $env:RUNNER_TEMP 'libplctag-tools'
-    Expand-Archive $zip -DestinationPath $dest
-    Add-Content $env:GITHUB_PATH $dest
+    docker compose -f tests/ZB.MOM.WW.OtOpcUa.Driver.AbCip.IntegrationTests/Docker/docker-compose.yml `
+      --profile controllogix up -d --build
+    # Wait for :44818 to accept connections (compose healthcheck-equivalent)
+    for ($i = 0; $i -lt 30; $i++) {
+      if ((Test-NetConnection -ComputerName localhost -Port 44818 -WarningAction SilentlyContinue).TcpTestSucceeded) { break }
+      Start-Sleep -Seconds 1
+    }
 ```
 
-The fixture's `LocateBinary()` picks the binary up off PATH so the C# harness doesn't own the download — CI YAML is the right place for version pinning + hash verification. Developer workstations install the binary once from source (`cmake + make ab_server` under a libplctag clone) and the same fixture works identically.
-
-Tests without ab_server on PATH are marked `Skip` via `AbServerFactAttribute` / `AbServerTheoryAttribute`, so fresh-clone runs without the simulator still pass all unit suites in this project.
+Tests skip via `AbServerFactAttribute` / `AbServerTheoryAttribute` when the probe fails, so fresh-clone runs without Docker still pass all unit suites in this project.
 
 ---