PLCOpen and OPC Foundation release new edition of PLCopen OPC-UA Client for IEC 61131-3

PLCOpen and OPC Foundation release new edition of PLCopen OPC-UA Client for IEC 61131-3

October 17, 2016 - PLCopen together with the OPC Foundation published a new edition of the definition of a set of Function Blocks providing OPC-UA client functionality. With this functionality implemented on a controller it becomes possible to initiate a communication session to any other available PLCopen OPC-UA Server. The controller can exchange complex data structures horizontally with other controllers independently from fieldbus system or vertically with other devices using an OPC-UA server call in an MES/ERP system in order to collect data or even write new production orders to the cloud. It allows a production line to be independently active in combination with integrated OPC-UA Security features.

The original version 1.0 was published 2 years ago, and during several implementations and feedback from additional supporting companies it became clear that additional as well as different functionality was needed, esp. concerning a better user interface and better usability. By specifying function blocks that deal with a “List” feature, one can work much easier with sets of data like variables or nodes. Now one can create a list of variables coupled to the required functionality, where originally one has to use a function block for each functionality and variable. This provides more effective programs with a better overview.

An OPC-UA client functionality in a controller does not provide hard deterministic real time and so it’s not a deterministic fieldbus – but OPC-UA provides fast and secure fieldbus independent communication, and provides modelling mechanism for information models.

This new edition is now published.

You can download this document PLCopen_OPC_UA_ClientFunctionBlocks_V1 1 as .pdf via the PLCopen website section Communication.

Overview of important changes V1.0 to V1.1

New functionalities:

- Created new Structured Data Type UANodeInformation
- Created new Function blocks with “List” functionality
- UA_NamespaceGetIndexList, UA_ServerGetIndexByUriList,
- UA_TranslatePathList
- UA_NodeGetHandleList, UA_NodeReleaseHandleList
- UA_NodeGetInformation
- UA_MonitoredItemAddList, UA_MonitoredItemRemoveList
- UA_MonitoredItemModifyList, UA_MonitoredItemOperateList
- UA_MethodeGetHandleList, UA_MethodReleaseHandleList
- UA_EventItemAdd, UA_EventItemOperate, UA_EventItemRemove

- UA_HistoryUpdate

And as a result, these Functions blocks are moved to a new chapter “Phased out Functions blocks”:

- UA_NamespaceGetIndex
- UA_TranslatePath
- UA_NodeGetHandle, UA_ReleaseHandle, UA_NodeGetInfo
- UA_SubscriptionOperate
- UA_MonitoredItemAdd, UA_MonitoredItemRemove, UA_MonitoredItemOperate
- UA_Read, UA_Write
- UA_MethodeGetHandle, UA_MethodeReleaseHandle

Other changes:

- Renamed UA_NodeClass to UA_NodeClassMask

- Enum value changed in UAIdentifierType

- Extend UAMonitoredSettings with parameter QueueSize

- Depricated Structed Data Type UANodeInfo

- The graphical representation of the order of the outputs of the FB’s have been harmonized: Done, Busy, Error; ErrorID, then general outputs, and finaly the VAR_IN_OUTs. For this reason we separate between V1.0 and V1.1 in the compliance list.

Added Appendix about Compliance procedure and make use of PLCopen OPC UA logo

About PLCopen

PLCopen was founded in 1992 as an independent worldwide association for industrial suppliers and users. It is the leading association resolving topics related to industrial control programming. PLCopen creates concepts to reduce the costs of industrial automation.

About OPC Foundation

The OPC Foundation defines standards for online data exchange between automation systems. They address access to current data (OPC DA), alarms and events (OPC A&E) and historical data (OPC HDA). Those standards are successfully applied in industrial automation.