Siemens Opcenter Execution

Technical Preview

Overview

One client-mode connector, SiemensOpcenterExecution, for the service layer of Siemens Opcenter Execution. Opcenter Execution Discrete, Process and other solutions built on Opcenter Execution Foundation expose the same surface: OData v4 reads on /sit-svc, a read-only archive on /sit-arch, and public commands that the solution’s workers execute. Use the connector to bring MES context into your Unified Namespace: publish active work orders next to the machine data that serves them, count open operations per line, or look up a finished order in the archive. In the other direction, a machine event on the broker can call an Opcenter command such as completing an operation or recording a consumption. Every Opcenter solution is different. Entity sets and command names come from the Apps installed in your solution, and Opcenter generates an OpenAPI 3.0.3 description of them when the solution is built. Start with the discovery events, then use the exact names they return.

Event	Request	Notes
GetPlantConfig	`GET /sit-svc/config?{query}`	Configured plants; `plantid=<PlantId>` filters one
GetHostMonitoring	`GET /sit-svc/monitoring?{query}`	Host and worker status, the data behind the Solution Studio monitoring screen
GetSolutionOpenApi	`GET /sit-svc/{solution_path}/$openapi`	OpenAPI of every public command in the solution
GetAppServiceDocument	`GET /sit-svc/{app_path}/odata/`	OData service document: the App’s entity sets
GetAppMetadata	`GET /sit-svc/{app_path}/odata/$metadata`	CSDL XML: entities, keys, properties, navigation
GetAppOpenApi	`GET /sit-svc/{app_path}/odata/$openapi`	OpenAPI of the App’s commands and entities
QueryEntities	`GET /sit-svc/{app_path}/odata/{entity}?{query}`	Any entity set with `$filter`, `$select`, `$expand`, `$orderby`, `$top`, `$skip`
GetEntity	`GET /sit-svc/{app_path}/odata/{entity}({key})?{query}`	One record by key
CountEntities	`GET /sit-svc/{app_path}/odata/{entity}/$count?{query}`	Plain-text count
ListWorkOrders	`GET /sit-svc/{app_path}/odata/WorkOrder?{query}`	Shortcut for the `WorkOrder` entity set; check the name in `$metadata`
QueryArchive	`GET /sit-arch/{app_path}/odata/{entity}?{query}`	Archived runtime data, read-only
InvokeCommand	`POST /sit-svc/{app_path}/odata/{command}`	Any public command; body as described in `$openapi`

Topics are mes/siemens-opcenter-execution/<object>/<verb>; every reply goes to <topic>/response. app_path is Application/<AppName> for the default plant, or <PlantId>/Application/<AppName> in a multi-plant installation, for example Application/AppU4DM or Plant1/Application/AppU4DM. solution_path is Application or <PlantId>/Application.

Authentication

Every event sends Authorization: {authorization}, so pass the whole header value, normally "Bearer <access token>". Opcenter issues tokens through its authentication service (/sit-auth), backed by Siemens UMC or the identity provider your installation is configured with. How a service account gets a token depends on that setup, so ask your Opcenter administrator for a service account and the token procedure, and give the account only the roles the commands you plan to call need. Keep the value in a broker secret (suggested OPCENTER_AUTHORIZATION) and map it in with GET SECRET. Tokens expire, so refresh the secret on the schedule your identity provider uses. A missing or expired token returns 401; a role without permission returns 403.

Basic Syntax

Opcenter runs on your own servers or private cloud, so set BASE_ADDRESS to the host that serves /sit-svc (no trailing slash).

DEFINE ROUTE SiemensOpcenterExecution WITH TYPE REST_API
    ADD REST_API_CONFIG
        WITH BASE_ADDRESS "https://YOUR_OPCENTER_HOST"
        WITH ENABLE_CLIENT "true"
        WITH USE_SSL "true"
        WITH REQUEST_TIMEOUT '60'
        WITH DEFAULT_CONTENT_TYPE "application/json"
    ADD EVENT QueryEntities
        WITH SOURCE_TOPIC "mes/siemens-opcenter-execution/entity/query"
        WITH DESTINATION_TOPIC "mes/siemens-opcenter-execution/entity/query/response"
        WITH METHOD "GET"
        WITH ENDPOINT "/sit-svc/{value.json.app_path}/odata/{value.json.entity}?{value.json.query}"
        WITH HEADERS
            ADD "Accept" "application/json"
            ADD "Authorization" "{value.json.authorization}"
    ADD EVENT InvokeCommand
        WITH SOURCE_TOPIC "mes/siemens-opcenter-execution/command/invoke"
        WITH DESTINATION_TOPIC "mes/siemens-opcenter-execution/command/invoke/response"
        WITH METHOD "POST"
        WITH ENDPOINT "/sit-svc/{value.json.app_path}/odata/{value.json.command}"
        WITH HEADERS
            ADD "Accept" "application/json"
            ADD "Content-Type" "application/json"
            ADD "Authorization" "{value.json.authorization}"
        WITH BODY "{value.json.body}"

The full template, with all 12 events, is SiemensOpcenterExecutionRestApi.lot in the REST API app.

MQTT examples

Request bodies go under body, so control fields like authorization, app_path, entity and query are not sent to Opcenter. Discover what an App offers: publish to mes/siemens-opcenter-execution/app-openapi/get:

{
  "authorization": "Bearer <Opcenter token>",
  "app_path": "Application/AppU4DM"
}

The reply lists the App’s commands with their request schemas. app-metadata/get returns the entity sets and keys. Read the first 20 work orders: publish to mes/siemens-opcenter-execution/work-order/list. The OData query must be URL-encoded:

{
  "authorization": "Bearer <Opcenter token>",
  "app_path": "Application/AppU4DM",
  "query": "$top=20"
}

Use entity/query with "entity": "<EntitySet>" for any other entity set, and send "query": "" when you do not need options. Get one record: publish to mes/siemens-opcenter-execution/entity/get with "entity" and "key". The key is the OData key literal as it appears in the URL: a Guid as is, a string in single quotes such as "'WO-0001'". Call a public command: publish to mes/siemens-opcenter-execution/command/invoke:

{
  "authorization": "Bearer <Opcenter token>",
  "app_path": "Application/<AppName>",
  "command": "<PublicCommandName>",
  "body": { "...": "fields exactly as the command's request schema in $openapi" }
}

The connector sends body unchanged, so copy its shape from the command’s schema in GetAppOpenApi or GetSolutionOpenApi.

Helper actions

Keep the token in a broker secret, poll work orders every minute, and turn a line event into an Opcenter command:

DEFINE ACTION OpcenterPollActiveWorkOrders
ON EVERY 1 MINUTE DO
    SET "auth" WITH GET SECRET "OPCENTER_AUTHORIZATION"
    PUBLISH TOPIC "mes/siemens-opcenter-execution/work-order/list" WITH { "authorization": {auth}, "app_path": "Application/AppU4DM", "query": "$top=50" }

DEFINE ACTION OpcenterInvokeFromLine
ON TOPIC "porto/line1/opcenter/command" DO
    SET "auth" WITH GET SECRET "OPCENTER_AUTHORIZATION"
    SET "cmd" WITH GET JSON "command" IN PAYLOAD AS STRING
    SET "args" WITH GET JSON "body" IN PAYLOAD
    PUBLISH TOPIC "mes/siemens-opcenter-execution/command/invoke" WITH { "authorization": {auth}, "app_path": "Application/AppU4DM", "command": {cmd}, "body": {args} }

Restrict who can publish to mes/siemens-opcenter-execution/# with a rule: its payloads carry the token, and InvokeCommand changes production records.

Notes

Errors come back on the response topic: 401 for a missing or expired token, 403 when the account’s role does not allow the call, 404 for an unknown App, entity set or command, 400 for a malformed OData query or command body, and 500 when a command handler fails.
Commands are executed by Opcenter workers. Some return only after the transaction commits; check the result by reading the affected entity afterwards.
/sit-arch is the archive database and is read-only. Use it for history and audit, and /sit-svc for live production data.
In a multi-plant installation each plant has its own data. Put the plant id in app_path and use GetPlantConfig with plantid=<PlantId> to check it.
Names differ between Opcenter Execution Discrete, Process and custom solutions. ListWorkOrders assumes a WorkOrder entity set; if your App names it differently, use QueryEntities.

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Overview

Authentication

Basic Syntax

MQTT examples

Helper actions

Notes

​Overview

​Authentication

​Basic Syntax

​MQTT examples

​Helper actions

​Notes

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Overview

Authentication

Basic Syntax

MQTT examples

Helper actions

Notes

Related