lmxopcua/tests/ZB.MOM.WW.OtOpcUa.Driver.AbLegacy.IntegrationTests/Docker/README.md

AB Legacy PCCC integration-test fixture — ab_server (Docker)

libplctag's ab_server supports both CIP (ControlLogix / CompactLogix / Micro800) and PCCC (SLC 500 / MicroLogix / PLC-5) families from one binary. This fixture reuses the AB CIP Docker image (otopcua-ab-server:libplctag-release) with different --plc flags. No new Dockerfile needed — the compose file's build: block points at the AB CIP Docker/ folder so docker compose build from here reuses the same multi-stage build.

Docker is the only supported launch path; a fresh clone needs Docker Desktop and nothing else.

File	Purpose
docker-compose.yml	Three per-family services (slc500 / micrologix / plc5); all bind :44818

Run

From the repo root:

# SLC 500 family — widest PCCC coverage
docker compose -f tests\ZB.MOM.WW.OtOpcUa.Driver.AbLegacy.IntegrationTests\Docker\docker-compose.yml --profile slc500 up

# Per-family
docker compose -f tests\...\Docker\docker-compose.yml --profile micrologix up
docker compose -f tests\...\Docker\docker-compose.yml --profile plc5 up

Detached + stop:

docker compose -f tests\...\Docker\docker-compose.yml --profile slc500 up -d
docker compose -f tests\...\Docker\docker-compose.yml --profile slc500 down

First run builds the otopcua-ab-server:libplctag-release image (~3-5 min — clones libplctag + compiles ab_server). If the AB CIP fixture already built the image locally, docker reuses the cached layers + this runs in seconds. Only one family binds :44818 at a time; to switch families stop the current service + start another.

Endpoint

• Default: localhost:44818 (EtherNet/IP standard)
• Override with AB_LEGACY_ENDPOINT=host:port to point at a real SLC / MicroLogix / PLC-5 PLC on its native port.

Run the integration tests

In a separate shell with a container up:

cd C:\Users\dohertj2\Desktop\lmxopcua
dotnet test tests\ZB.MOM.WW.OtOpcUa.Driver.AbLegacy.IntegrationTests

AbLegacyServerFixture TCP-probes localhost:44818 at collection init + records a skip reason when unreachable. Tests use [AbLegacyFact] / [AbLegacyTheory] which check the same probe.

What each family seeds

PCCC tag format is <file>[<size>] without a type suffix — file letter implies type:

• N = 16-bit signed integer
• F = 32-bit IEEE 754 float
• B = 1-bit boolean (stored as uint16, bit-addressable via /n)
• L = 32-bit signed integer (SLC 5/05 V15+ only)
• ST = 82-byte ASCII string (MicroLogix-specific extension)

Family	Seeded tags	Notes
SLC 500	N7[10], F8[10], B3[10], L19[10]	Baseline; covers the four numeric file types a typical SLC project uses
MicroLogix	B3[10], N7[10], L19[10]	No F8 — MicroLogix 1000 has no float file; use L19 when scaled integers aren't enough
PLC-5	N7[10], F8[10], B3[10]	No L — PLC-5 predates the L file type; DINT equivalents went in integer files

Known limitations

ab_server PCCC read/write round-trip (verified 2026-04-20)

Scaffold is in place; wire-level round-trip does NOT currently pass against ab_server --plc=SLC500. With the SLC500 compose profile up, TCP 44818 accepts connections and libplctag negotiates the session, but the three smoke tests in AbLegacyReadSmokeTests.cs all fail at read/write with BadCommunicationError (libplctag status 0x80050000). Possible root causes:

• ab_server's PCCC server-side opcode coverage may be narrower than libplctag's PCCC client expects — the tool is primarily a CIP server; PCCC was added later + is noted in libplctag docs as less mature.
• libplctag's PCCC-over-CIP encapsulation may assume a real SLC 5/05 EtherNet/IP NIC's framing that ab_server doesn't emit.

The scaffold ships as-is because:

1. The Docker infrastructure + fixture pattern works cleanly (probe passes, container lifecycle is clean, tests skip when absent).
2. The test classes target the correct shape for what the AB Legacy driver would do against real hardware.
3. Pointing AB_LEGACY_ENDPOINT at a real SLC 5/05 / MicroLogix 1100 / 1400 should make the tests pass outright — the failure mode is ab_server-specific, not driver-specific.

Resolution paths (pick one):

1. File an ab_server bug in libplctag/libplctag to expand PCCC server-side coverage.
2. Golden-box tier via Rockwell RSEmulate 500 — closer to real firmware, but license-gated + RSLinx-dependent.
3. Lab rig — used SLC 5/05 / MicroLogix 1100 on a dedicated network; the authoritative path.

Other known gaps (unchanged from ab_server)

• Timer / Counter file decomposition — PCCC T4 / C5 files contain three-field structs (.ACC / .PRE / .DN). Not in ab_server's scope; tests targeting T4:0.ACC stay unit-only.
• ST (ASCII string) files — real MicroLogix ST files have a length field plus CRLF-sensitive semantics that don't round-trip cleanly.
• Indirect addressing (N7:[N10:5]) — not in ab_server's scope.
• DF1 serial wire behaviour — the whole ab_server path is TCP; DF1 radio / serial fidelity needs real hardware.

See docs/drivers/AbLegacy-Test-Fixture.md for the full coverage map.

References

• libplctag on GitHub — ab_server lives under src/tools/ab_server/
• docs/drivers/AbLegacy-Test-Fixture.md — coverage map + gap inventory
• docs/v2/dev-environment.md §Docker fixtures — full fixture inventory
• ../../ZB.MOM.WW.OtOpcUa.Driver.AbCip.IntegrationTests/Docker/ — the shared Dockerfile this compose file's build: block references