FAQ - frequently asked questions and answers

What performance can be achieved with the TwinCAT Database Server?
This question cannot be answered in general terms. The performance that can be achieved depends on the hardware used, the actions to be execute (e.g. ring buffer logging) and the number of variables. Another key factor is the database type that is used.

Are so-called Stored Procedures supported?
Yes, the TwinCAT Database Server supports Stored Procedures. The function block FB_SQLStoredProcedure is provided for this purpose in the PLC library. The SQL Query Editor can be used to test stored procedures, and corresponding PLC code for the function block FB_SQLStoredProcedure can be generated. Not all databases support this function.

Which database types does the TwinCAT Database Server support?
Information on the supported databases can be found in section "Databases".

Can old database server configurations still be used in later versions?
It goes without saying that we aim to ensure compatibility. This was also taken into account during major version upgrades or complete redesigns (e.g. old: 3.0.x, new: 3.1.x). Further details can be found in section "Compatibility".

How can individual variables be written into an existing database structure or read from it?
The function block FB_SQLCommand can be used to write individual variables into an existing database structure or read from it.

Can several records be written into a database simultaneously?
This depends on the database used. With a Microsoft SQL database this would be possible in conjunction with the function block FB_SQLCommand, since several SQL insert commands (separated by semicolon) can be transferred to the PLC function block.

How can the TwinCAT Database Server be operated in a network?
The TwinCAT Database Server can be used in a network in several ways. Further information on support network topologies can be found in section "Areas of application and network topologies".

Which functions of the TwinCAT Database Server are supported by the database type "XML"?
The "XML" database type supports the full functionality of the TwinCAT Database Server, except for "stored procedures". The XML file can be used to communicate with any other database via SQL commands, and PLC values can be logged in the XML file with the cyclic write mode. In addition, it is possible to execute XPath commands and read the corresponding XML tags. Further information can be found in section "XML database".

Which Visual Studio versions are currently supported by the database server configurator?

Currently the Visual Studio® versions 2013, 2015 and 2017 are supported with our configurator integration.