open62541 ========= open62541 (http://open62541.org) is an open source and free implementation of OPC UA (OPC Unified Architecture). open62541 is a C-based library that contains all the necessary tools to set up a dedicated OPC UA server, to integrate OPC UA-based communication into existing applications (linking with C++ projects [is possible](examples/server.cpp)), or to create an OPC UA client. The library is distributed as a single pair of [header](http://open62541.org/open62541.h) and [source](http://open62541.org/open62541.c) files, that can be easily dropped into your project. An example server and client implementation can be found in the [/examples](examples/) directory or further down on this page. open62541 is licensed under the LGPL + static linking exception. That means **open62541 can be freely used also in commercial projects**, although changes to the open62541 library itself need to be released under the same license. The server and client implementations in the [/examples](examples/) directory are in the public domain (CC0 license). They can be used under any license and changes don't have to be published. [![Ohloh Project Status](https://www.ohloh.net/p/open62541/widgets/project_thin_badge.gif)](https://www.ohloh.net/p/open62541) [![Build Status](https://travis-ci.org/acplt/open62541.png?branch=master)](https://travis-ci.org/acplt/open62541) [![Coverage Status](https://coveralls.io/repos/acplt/open62541/badge.png?branch=master)](https://coveralls.io/r/acplt/open62541?branch=master) [![Coverity Scan Build Status](https://scan.coverity.com/projects/1864/badge.svg)](https://scan.coverity.com/projects/1864) ### Documentation A general introduction to OPC UA and the open62541 documentation can be found at http://open62541.org/doc. Build instruction are here: https://github.com/acplt/open62541/wiki/Building-open62541. For discussion and help, you can use - the [mailing list](https://groups.google.com/d/forum/open62541) - our [IRC channel](http://webchat.freenode.net/?channels=%23open62541) - the [bugtracker](https://github.com/acplt/open62541/issues) ### Contribute to open62541 As an open source project, we invite new contributors to help improving open62541. If you are a developer, your bugfixes and new features are very welcome. Note that there are ways to contribute even without deep knowledge of the project or the UA standard: - [Report bugs](https://github.com/acplt/open62541/issues) - Improve the [documentation](http://open62541.org/doc) - Work on issues marked as "[easy hacks](https://github.com/acplt/open62541/labels/easy%20hack)" ### Example Server Implementation Compile the examples with the single file distribution `open62541.h` and `open62541.c` from the latest [release](https://github.com/acplt/open62541/releases). With the GCC compiler, just run ```gcc -std=c99 open62541.c -o server```. ```c #include #include "open62541.h" #define WORKER_THREADS 2 /* if multithreading is enabled */ #define PORT 16664 UA_Boolean running = UA_TRUE; void signalHandler(int sign) { running = UA_FALSE; } int main(int argc, char** argv) { /* catch ctrl-c */ signal(SIGINT, signalHandler); /* init the server */ UA_Server *server = UA_Server_new(); UA_Server_addNetworkLayer(server, ServerNetworkLayerTCP_new(UA_ConnectionConfig_standard, PORT)); UA_Server_setLogger(server, Logger_Stdout_new()); /* add a variable node */ UA_Variant *myIntegerVariant = UA_Variant_new(); UA_Int32 myInteger = 42; UA_Variant_setScalarCopy(myIntegerVariant, &myInteger, &UA_TYPES[UA_TYPES_INT32]); UA_QualifiedName myIntegerName = UA_QUALIFIEDNAME(1, "the answer"); UA_NodeId myIntegerNodeId = UA_NODEID_STRING(1, "the.answer"); UA_NodeId parentNodeId = UA_NODEID_NUMERIC(0, UA_NS0ID_OBJECTSFOLDER); UA_NodeId parentReferenceNodeId = UA_NODEID_NUMERIC(0, UA_NS0ID_ORGANIZES); UA_Server_addVariableNode(server, myIntegerVariant, myIntegerName, myIntegerNodeId, parentNodeId, parentReferenceNodeId); /* run the server loop */ UA_StatusCode retval = UA_Server_run(server, WORKER_THREADS, &running); UA_Server_delete(server); return retval; } ``` ### Example Client Implementation ```c #include #include "open62541.h" int main(int argc, char *argv[]) { UA_Client *client = UA_Client_new(); UA_ClientNetworkLayer nl = ClientNetworkLayerTCP_new(UA_ConnectionConfig_standard); UA_StatusCode retval = UA_Client_connect(client, UA_ConnectionConfig_standard, nl, "opc.tcp://localhost:16664"); if(retval != UA_STATUSCODE_GOOD) { UA_Client_delete(client); return retval; } // Browse nodes in objects folder UA_BrowseRequest bReq; UA_BrowseRequest_init(&bReq); bReq.requestedMaxReferencesPerNode = 0; bReq.nodesToBrowse = UA_BrowseDescription_new(); bReq.nodesToBrowseSize = 1; bReq.nodesToBrowse[0].nodeId = UA_NODEID_NUMERIC(0, UA_NS0ID_OBJECTSFOLDER); //browse objects folder bReq.nodesToBrowse[0].resultMask = UA_BROWSERESULTMASK_ALL; //return everything UA_BrowseResponse bResp = UA_Client_browse(client, &bReq); printf("%-9s %-16s %-16s %-16s\n", "NAMESPACE", "NODEID", "BROWSE NAME", "DISPLAY NAME"); for (int i = 0; i < bResp.resultsSize; ++i) { for (int j = 0; j < bResp.results[i].referencesSize; ++j) { UA_ReferenceDescription *ref = &(bResp.results[i].references[j]); if(ref->nodeId.nodeId.identifierType == UA_NODEIDTYPE_NUMERIC){ printf("%-9d %-16d %-16.*s %-16.*s\n", ref->browseName.namespaceIndex, ref->nodeId.nodeId.identifier.numeric, ref->browseName.name.length, ref->browseName.name.data, ref->displayName.text.length, ref->displayName.text.data); }else if(ref->nodeId.nodeId.identifierType == UA_NODEIDTYPE_STRING){ printf("%-9d %-16.*s %-16.*s %-16.*s\n", ref->browseName.namespaceIndex, ref->nodeId.nodeId.identifier.string.length, ref->nodeId.nodeId.identifier.string.data, ref->browseName.name.length, ref->browseName.name.data, ref->displayName.text.length, ref->displayName.text.data); } //TODO: distinguish further types } } UA_BrowseRequest_deleteMembers(&bReq); UA_BrowseResponse_deleteMembers(&bResp); UA_Int32 value = 0; //Read node's value UA_ReadRequest rReq; UA_ReadRequest_init(&rReq); rReq.nodesToRead = UA_ReadValueId_new(); rReq.nodesToReadSize = 1; rReq.nodesToRead[0].nodeId = UA_NODEID_STRING(1, "the.answer"); rReq.nodesToRead[0].attributeId = UA_ATTRIBUTEID_VALUE; UA_ReadResponse rResp = UA_Client_read(client, &rReq); if(rResp.responseHeader.serviceResult == UA_STATUSCODE_GOOD && rResp.resultsSize > 0 && rResp.results[0].hasValue && rResp.results[0].value.data /* an empty array returns a null-ptr */ && rResp.results[0].value.type == &UA_TYPES[UA_TYPES_INT32]){ value = *(UA_Int32*)rResp.results[0].value.data; printf("the value is: %i\n", value); } UA_ReadRequest_deleteMembers(&rReq); UA_ReadResponse_deleteMembers(&rResp); value++; // Write node's value printf("\nWriting a value of node (1, \"the.answer\"):\n"); UA_WriteRequest wReq; UA_WriteRequest_init(&wReq); wReq.nodesToWrite = UA_WriteValue_new(); wReq.nodesToWriteSize = 1; wReq.nodesToWrite[0].nodeId = UA_NODEID_STRING_ALLOC(1, "the.answer"); /* assume this node exists */ wReq.nodesToWrite[0].attributeId = UA_ATTRIBUTEID_VALUE; wReq.nodesToWrite[0].value.hasValue = UA_TRUE; wReq.nodesToWrite[0].value.value.type = &UA_TYPES[UA_TYPES_INT32]; wReq.nodesToWrite[0].value.value.storageType = UA_VARIANT_DATA_NODELETE; //do not free the integer on deletion wReq.nodesToWrite[0].value.value.data = &value; UA_WriteResponse wResp = UA_Client_write(client, &wReq); if(wResp.responseHeader.serviceResult == UA_STATUSCODE_GOOD) printf("the new value is: %i\n", value); UA_WriteRequest_deleteMembers(&wReq); UA_WriteResponse_deleteMembers(&wResp); UA_Client_disconnect(client); UA_Client_delete(client); return UA_STATUSCODE_GOOD; } ```