Light OPC
The Free OPC Server Toolkit

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2004 November 17     - FAQ updated.

The LightOPC has been designed by enthusiasts of the Lab43 team during September - December 2000 as free and powerful alternative to commercial OPC development toolkits. First public version was released 8 March 2001.

This software provides easy way to implement full functional and fast OPC servers (both OPC/DA v1 & v2 custom interface supported) on Win32 platforms.

Internal architecture of this server toolkit has several advantages and provides noticeable high performance. Data layout is optimized for better usage of CPU cache. Threads synchronization designed in SysV style (including implementation of read-write locks and conditions). In addition to restricted usage of OLE/COM and Win32 API (and no ATL used) it provides high portability of source code.

Examples for in-proc (DLL) and out-of-proc (EXE) server are included in this distribution.

See FAQ for reference.


The LightOPC is distributed under LGPL v.2 conditions (see online at

lightopc-0.888-0313bin [.tgz] [.bz2]   - complete built libraries; includes samples, headers and projects 140k
lightopc-0.888-0313 [.tgz] [.bz2]   - library sources 150k
unilog-0.55-1227 [.tgz] [.bz2]   - the logging library sources is required for building the LightOPC 25k   - a more complex sample of OPC server for L-Card hardware. The L-Card supporting library is required to build this server. 57k
ntse-1.04.tgz   - The helper library for writing NT-services. Works on either NT/2k or Win95/98 (emulated SCM).
Included sample of OPC server is 3 times shorter than one in lightopc package.
A lightopc-*bin package required.

The older versions of this software available at

The latest changes are described in release history.

The binaries can be built using either MINGW32/gcc (see or MS Visual C++.

You probably have to obtain some standard OPC files from OPC Foundation.
The standard OPC headers and GUID definitions files are required to build the LightOPC library.
The proxy-stubs and manuals also may be required.
These files are located somewhere at -- look for:

We are providing gzip and bzip2 archives. The bzip2 ones are smaller in size. You may download bzip2 capable archievers at: or

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Contact:     master AT ipi ac ru