OPC UA (OPC Unified Architecture) is a protocol for industrial communication and has been standardized in the IEC62541. OPC UA defines a set of services to interact with a server-side object-oriented information model. Besides the service-calls initiated by the client, push-notification of remote events (such as data changes) can be negotiated with the server. The client/server interaction is mapped to a binary encoding and TCP-based transmission.
OPC UA function block API
C-coded clients for QNX 6.x are only supported by porting the open source project open62541.org