History, event and data access to 800xA with 800xAHistory server installed
As we know that there are several interfaces for 3rd control system including MES (Manufacturing Execution System ) to access data from 800xA .
Our customer wants realtime data , history data and event from our 800xA (version 6.0.3) to their MES system.
My question is..
Which connectivity is recommeded by ABB or is the preferable choice from ABB. I am thinking about the load of the system when MES is connected/ additionanl cost for license and any other security points of view.
1) Via OPC Server but should we use DA/HDA or UA ?
- OPC DA to access realtime data (OpcDaSurrogate?)
- OPC HDA to access history data ( AdvHtHistoryServer?)
- OPC UA to access real time and history data
2) via ODBC Interface to access numerric as well as event data.
Hope that I don't misunderstand something, please advise if I do.
Voted best answer
I cannot answer for 800xA History.
OPC UA is not yet supported by System 800xA; only traditional OPC DA, AE and HDA. The System 800xA Configuration User's Guide contain more info about OPC server names, required DCOM settings, etc.
OPC DA: OpcDAServer (local COM only) or OpcDASurrogate (COM+DCOM)
OPC AE: OPCEventServer.1 (local COM only)
OPC HDA: AdvHtHDAHdlr (local COM only) or AdvHtHDASrv.1 (COM+DCOM)
There is also some ODBC support I would soon start calling legacy. I believe OPC has taken over the main "data inteface" role in modern systems.
Currently, no license is enforced but this may change in any future version so ensure you purchase a license for 3rd party OPC connection.
System loading is one of the most difficult things to predict and deliver promises for.
E.g. OPC DA access may (will) put the client load directly on the OPC server(s) and PLCs responsible for that data. Some "connects" within the 800xA family are "strong" (when well tuned) and could handle tens of thousands of items, likewise, there are weaker connects and connects not properly tuned where a modest increase in OPC DA access could stir up problems or worse.
There is a BIG difference between a "scanning" client vs a "subscribing" client, likewise a "reading" client is most often easier to accomodate than a "writing" client. It's more or less virtually impossible to predict system load impact without a very clear description on what items, their origin (type of PLC within the system) are being subscribed/scanned/written and via what OPC interfaces and by what frequencies..
OPC HDA and OPC AE access land on the historian of choice or the 800xA system's Alarm Manager service, not directly onto the PLCs. However, each server has a limited performance envelope and care must be taken to prevent overloading the system - it may have negative effect on operations and/overall system stability.