Supported features and limits#

What engiNIR-OPCUA implements, and what it does not implement yet. The baseline is OPC 10000 v1.05; peers that speak 1.04 are accepted.

Supported#

Area	Supported
Transport	`opc.tcp` with the UA binary encoding (OPC 10000-6, 7.1), including reverse connect (7.1.2.6)
Security policies	Basic256Sha256, Aes128_Sha256_RsaOaep and Aes256_Sha256_RsaPss with Sign or SignAndEncrypt; None. The deprecated Basic256 and Basic128Rsa15 only in the `legacy` profile
User identity	Anonymous, user name and password, X.509 certificate
Client services	Discovery, sessions, browse and translate, read and write, methods, subscriptions with data changes and events, history read (raw values and events), subscription transfer, reconnect, redundant servers (`HaClient`)
Server services	Discovery (also as a discovery server with `accept_server_registrations`), sessions, the view, attribute, method, node management, monitored item and subscription services, history read of raw values and events
Information model	Custom object, variable, data and event types; structures, unions, enumerations and OptionSets with their DataTypeDefinition; NodeSet2 import and export; companion specifications such as DI, ADI, LADS and Machinery
Server features	Alarms and conditions, history storage in memory or SQLite, file transfer (FileType and FileDirectoryType), Program state machines, diagnostics, model change events, certificate management over OPC UA (OPC 10000-12 push management)
PubSub	Experimental: UADP over UDP; see PubSub (experimental)
APIs	asyncio, and a blocking API (Synchronous Interface) with the same methods

Area	Not supported
Security policies	The ECC policies (ECC_nistP256, ECC_nistP384, ECC_brainpoolP256r1, ECC_brainpoolP384r1) and the channel-bound session signatures that come with them (OPC 10000-4, 6.1.8)
Transports and encodings	HTTPS, WebSockets (`opc.wss`) and the JSON encoding (OPC 10000-6, 5.4); XML only for NodeSet files
Server services	HistoryUpdate, QueryFirst and QueryNext, FindServersOnNetwork; they answer `Bad_ServiceUnsupported`
History read	Processed (aggregates), at-time and modified values, annotations; they answer `Bad_HistoryOperationUnsupported`
Certificate management	The pull model and a Global Discovery Server; only push management is implemented
PubSub	Message security, JSON, MQTT, chunking and the configuration methods