Testing and interop

OT Fabric tests its IEC 61850 stack against two independent implementations, in both directions: OT Fabric as client against a reference server, and a reference client against the OT Fabric server. This page lists the tools, how to run them, and exactly what the evidence covers.

Simulators you can run locally

Simulator	What it is	Good for
`iec61850ctl server start --scl file.icd`	The go-iec61850 server driven by any ICD, CID or SCD, with optional value seeding from a live device	Trying reads, reports and controls against your own model
go-iec61850 `NewServer`	The same server embedded in your Go program, with `RegisterControl`, `SetValue` and the report engine	Test fixtures in Go code
`libiec61850-ied-server` (mms-interop)	libiec61850 IED server loaded with the interop fixture	An independent C reference
`iec61850bean-ied-server` (mms-interop)	IEC61850bean IED server loaded with the interop fixture	An independent Java reference
`libiec61850-mms-server` (mms-interop)	Generic MMS server (no IEC 61850 model)	Raw MMS with go-mms

Self-tests where an OT Fabric client talks to an OT Fabric server are useful for smoke testing but are not interoperability evidence.

mms-interop

mms-interop owns the adapter images and fixtures, not the assertions. Assertions live in go-mms, go-iec61850 and iec61850ctl.

The current adapter version is 0.1.4 with fixture revision iec61850-v2. Two images are published:

Image	Stack	Commands
`mms-interop-libiec61850`	libIEC61850, built from a pinned release archive (GPLv3, runs in its own container, never linked into the Go libraries)	`libiec61850-mms-server`, `-mms-client`, `-ied-server`, `-ied-client`, `-ied-controller`, `-ied-reporter`
`mms-interop-iec61850bean`	IEC61850bean 1.x (Apache-2.0), an independent ASN.1/BER, ACSE and MMS implementation	`iec61850bean-ied-server`, `-ied-client`, `-ied-controller`, `-ied-reporter`

IEC61850bean is used only at the IEC 61850 layer; generic MMS interop is covered through libiec61850. Every adapter command supports --capabilities and --version. The authoritative command list is fixtures/capabilities.json in the repository.

The IEC 61850 fixture is fixtures/iec61850/interop.icd plus values.json. It defines the IED InteropIED with the logical device InteropLD. Key objects:

Object	Purpose
`GGIO1.SPS1.stVal`, `Mod.stVal`	The two members of dataset `dsInterop`
`MMXU1.TotW.mag.f`	MX float read
`GGIO1.SPCSO1` / `SPCSO2` / `SPCSO3`	Direct, SBO and SBOw controls
`GGIO1.SetInt1.setVal[SP]`	Writable scalar setting (ING)
`urcb01`, `brcb01` in `LLN0`	Unbuffered and buffered RCBs

Adapter contract

A server adapter prints one readiness line on stdout before accepting connections, then the test connects:

{"event":"ready","address":"0.0.0.0:102","fixture":"iec61850-v1","adapter":"libiec61850","version":"0.1.0"}

Client adapters print one JSON line per operation ({"operation":"read","target":"interop/boolean","ok":true,"value":true}). Diagnostics go to stderr. Fixed-sequence *-ied-client adapters exit 3 when any operation fails and 2 on connection failure.

cd mms-interop
make build
docker run --rm -p 1102:1102 --entrypoint libiec61850-ied-server \
  mms-interop-libiec61850:local --port 1102

LIBIEC61850_IMAGE=ghcr.io/otfabric/mms-interop-libiec61850@sha256:9c29847dbd0523002b113a2fd1806cfb523bdd1610ae2e47f53b6156ec15fde7
docker run --rm -p 1102:1102 --entrypoint libiec61850-ied-server \
  "$LIBIEC61850_IMAGE" --port 1102

Then point iec61850ctl at it with IEC61850_IED_NAME=InteropIED:

export IEC61850_HOST=127.0.0.1 IEC61850_PORT=1102 IEC61850_IED_NAME=InteropIED
iec61850ctl list lds --format json
iec61850ctl get object --object InteropLD/MMXU1.TotW.mag.f --fc MX --format json

To drive the OT Fabric server with a reference client, start iec61850ctl server start --host 0.0.0.0 --port 1102 ... on the host and run the adapter with --add-host=host.docker.internal:host-gateway --host host.docker.internal.

Running the suites

The external and reverse suites need Docker. Tests start each adapter with docker run, wait for the readiness line, run, and tear down. Nothing has to be running beforehand.

LIBIEC61850_IMAGE=mms-interop-libiec61850:local make interop

Tests are behind -tags=interop. MMS_SERVER_BINARY and MMS_CLIENT_BINARY skip Docker and use local adapter binaries.

LIBIEC61850_IMAGE=mms-interop-libiec61850:local \
IEC61850BEAN_IMAGE=mms-interop-iec61850bean:local \
make interop

IEC61850_FIXTURE_DIR overrides the fixture path. Test names say the direction: TestLibIECClient_* (Go client, libiec61850 server), TestLibIECServer_* (Go server, libiec61850 client), TestBeanClient_*, TestBeanServer_*.

make build-nocheck
make e2e                                       # libiec61850, iec61850bean, self
IEC61850CTL_E2E_STACKS=server-libiec61850 make e2e
IEC61850CTL_E2E_STACKS=all make e2e            # every CI direction
make e2e-verify-fixtures                       # check fixture hashes against the lock file

The e2e package runs the built binary as a black box. Mutating journeys use isolated adapter servers. e2e/testdata/interop.lock.json pins mms-interop v0.1.4 by commit and image digest.

A test skipped without a registered limitation fails CI.

What has been validated

go-mms against libiec61850 (both directions)

Associate and conclude, reconnect, Identify, Status, GetNameList, GetVariableAccessAttributes, reads of every fixture type (boolean, integer, unsigned, float32, visible-string, octet-string, bit-string, utc-time, array, structure), single and multi-variable writes, named variable list define, read and delete, and negative cases (unknown domain or variable, wrong type, read-only write).

Not yet tested against a reference: InformationReport, file services and journal services.

go-iec61850 against libiec61850 and IEC61850bean

Area	Go → libIEC	libIEC → Go	Go → Bean	Bean → Go
Associate, browse LD/LN/DO, ST/MX/CF/DC reads	✓	✓	✓	✓
Write and read-back	✓	✓	✓	✓
Dataset list and read	✓	✓	✓	✓
URCB reserve, enable, data-change report, disable	✓	✓	✓	✓
URCB general interrogation	✓	✓	✓	not tested
Direct control	✓	✓	✓	✓
SBO (normal security)	✓	✓	✓	✓
SBOw (enhanced security)	✓	✓	known gap	n/a
Cancel	✓	✓	not tested	not tested
Integrity period	not tested	not tested	not tested	not tested
BRCB	not in matrix	not in matrix	not in matrix	not in matrix

CDC reads interop-tested: SPS, DPS, INS, ACT, SPC, DPC, MV and BCR. CMV, ENS and BSC are implemented but not interop-tested.

IEC61850bean as a server does not expose SBOw[CO] as a writable attribute, so SBOw from a Go client to IEC61850bean is a registered expected failure. IEC61850bean’s server also does not answer MMS Conclude; tests use Abort.

iec61850ctl end to end

The CLI suite adds black-box journeys through the binary: browse and reads against expected values, datasets, RCB discovery, URCB GI subscription in JSONL, control operate on SPCSO1/2/3 with --confirm-ref, set object on SetInt1.setVal[SP] with --verify, and BRCB purge and resume by EntryID (required against libiec61850; best effort against IEC61850bean). In the reverse direction, libiec61850 and IEC61850bean controllers, reporters and readers run against iec61850ctl server start. Negative cases cover control mode mismatch, confirmation mismatch and FC=CO rejection.

Not yet validated

Physical IEDs from any vendor.
External BRCB interoperability in the go-iec61850 library matrix (covered by Go-only integration tests and by the CLI against libiec61850).
Integrity-period reporting against a reference stack.
Edition 2.1 (2007B4) features beyond those listed.
Dynamic dataset creation on the server, CommandTermination and TimeActivatedOperate (not implemented).
File and journal services in reverse (reference client to OT Fabric server).
Adapter fault injection such as mid-sequence disconnects.