Free Stuff - OPC Servers

This page draws together all the information we have on freely available OPC servers.

The tools which appear on this page are all supplied free of charge, and are either pre-built or supplied as 'ready to build' source code, or both. Some are evaluation versions, and are identified as such. They may all be downloaded from the Web.

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Free OPC Servers by Matrikon OPC

Free OPC Servers




Free OPC Servers

Matrikon OPC

Various trial OPC Servers available for free (Modbus, DNP3, SCADA Modbus, APACS, SNMP, ..etc). Vast selection of devices, protocols and API is supported. View all OPC Servers' categories here.

Modbus OPC Server

Matrikon OPC

This Modbus OPC Server provides secure and reliable real-time data access between all Modbus devices and any OPC-enabled applications.

Allen Bradley OPC Server

Matrikon OPC

The Allen Bradley OPC Server from Matrikon OPC enables OPC access to PLC5, SLC500, Micrologix, and ControlLogix the most popular Allen Bradley PLCs.

Siemens S7 PLC OPC Server

Matrikon OPC

The Siemens S7 PLC OPC Server from Matrikon OPC provides industrial strength connectivity to the S7 family of PLCs (S7-200, S7-300, S7-400, S7 1200 and S7 1500 series) via Ethernet.

OPC Simulation Server for Testing

Matrikon OPC

Widely used OPC Simulation Server, compliant with DA 2.05, DA 3.00 and AE specifications, and also with HDA support. Watch this "How to Video" for quick setup

MBX OPC Server, DHX OPC Server


Time-limited versions of servers for Modicon and Allen-Bradley, supporting DA 1.0a, 2.05a and 3.0, AE 1.1 and XML-DA 1.0. Free licensing for non-production use is available.

Gray Simulator


Free simulation server, compliant with all DA standards. May be redistributed with no limitations.

Graybox OPC Server Toolkit Demo


Demo version of compliant DA server toolkit. Free download is restricted to 100 tags but otherwise unlimited.



Evaluation version of a combined OPC server and client package, including several I/O drivers. Very flexible, but user interface is sometimes confusing. Includes support for a proprietary protocol, offering a subset of OPC Data Access functionality, which uses XML data packets sent over HTTP.

dOPC Clone


Trial version of a revolutionary product which allows full emulation of other DA servers with no need for an underlying communications network. Invaluable for system development, configuration, and demonstration. dOPC Clone is DA 2.05a compliant.



Trial version of a DA server which monitors network status using either ICMP (Ping) or SNMP.

OPCTechs Demo OPC Server


Two-hour trial version of an OPC server supporting DA 2, DA 3, AE and XML-DA. A wide range of protocols is offered.

Prosys OPC Simulation Server


Fully compliant DA 2.05a server with source, demonstrating capabilities of the Prosys Sentrol rapid development framework.

Software Toolbox


Demo version of a product which allows the user to define his/her own serial or TCP/IP protocol without programming. Also supports DDE for legacy purposes. Requires restart after 60 minutes. Now certified DA 2.05a compliant.

TOP Server

Software Toolbox

Rebadged version of Kepware's KEPServerEX (above). Now DA 3.0 compliant.

OPC Simulation server and GUI client


In-process simulation server, supplied as an aid to compliance testing of OPC clients. Now has improved OPC Data Access 2 support and includes the updated proxy/stub DLL, as well as a simple client program (see clients).


OPC Server Demos

Restricted versions of various OPC servers, some now with DA 3 support.

Various servers

WinTECH Software is a simulation server supporting Data Access 2. It has some useful diagnostic aids: the user may control the profiles of the simulated data points, and all OPC interface calls are displayed in a logging window. Also available is a demo server for Historical Data Access.

Free OPC Servers

Matrikon OPC

Various trial OPC Servers available for free (Modbus, DNP3, SCADA Modbus, APACS, SNMP, ..etc). Vast selection of devices, protocols and API is supported. View all OPC Servers' categories here.

Our Source Code and Tools and Techniques pages carry more information on some of these tools, while our Links page offers some recommendations from third-party sites.

See also: