External interfaces

Introduction

External interfaces are used to read and write data from History. Different kinds of integration scenarios are main use case.

Vtrinlib is the most flexible interface and available as .NET client API. Other interfaces are built on top of Vtrinlib. VtrinLib is available also as REST API.

ODBC is a standard interface for databases, good alternative for maintenance and reporting.

OData API is good for doing calculations and analytics on top of History. It supports reading and writing timeseries data and reading structural data.

OPC UA Server implements standard interface to read and write data. Fits well with Vtrinlib and History.

OPC Classic Servers are widely used when legacy software should be integrated. Widely supported in the industry.

WSS Server API connections can be done with any standard WebSocket library compliant with RFC 6455.

Feature comparison

Feature comparison shows upper level view of functionalities available in each external interface. Vtrinlib, ODBC and OData are supported both in Windows and Linux, OPC Servers only in Windows. Classic OPC contains two servers OPC HDA Server and OPC DA Server and feature comparison is assuming both are used.


	Vtrinlib	ODBC	OData API	OPC Classic	OPC UA	WSS and REST
Reading classes and instances.	Yes	Yes	Yes 4)	No	Yes	Yes
Creating and updating classes and instances	Yes	Yes	Yes	No	Yes	Yes
Reading time series data	Yes	Yes	Yes	Yes	Yes	Yes
Writing time series data	Yes	Yes 1)	Yes	Yes 2)	Yes	Yes
Reading current values	Yes	Yes	Yes	Yes 3)	Yes	Yes
Subscribing current values	Yes	No	No	Yes 3)	Yes	Yes
Writing current values	Yes	Yes	Yes	Yes 3)	Yes	Yes

Writing time series data only available through UpdateHistory command class
Writing time series data requires to change OPC HDA Server to connect using database disk directly not using wss-connection (from %APP_DATAPATH%\Config\OpcIniFles\RtdbOpcHdaServer.ini)
Only from Tags/Variables, not from Equipment model
Only classes with Name or Id property are visible

Updated 5 months ago