Beckhoff TwinCAT

Licensing starts at $545.00
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Product Overview

The Beckhoff TwinCAT driver for KEPServerEX provides an easy and reliable way to connect Beckhoff's TwinCAT software system to your OPC client applications, including HMI, SCADA, Historian, MES, ERP, and countless custom applications.



  • Automatic Tag Database Generation Options - From Device or Import file (.tpy)
  • Import TwinCAT variables and specified OPC Item Properties
  • AMS Routing Support
  • Symbolic Based Addressing
  • Included TwinCAT Technical notes
  • Maximum TwinCAT System Connections - 50,000 (100 channels, 500 per channel)


  • Beckhoff ADS API

Supported Devices

  • BC9xxx Coupler Controller
  • Beckhoff TwinCAT PLC
  • BX9xxx Coupler Controller

Available Languages

  • English

Application Support

  • DDE Format CF_Text and AdvancedDDE
  • NIO Interface for iFIX
  • OPC .NET Service (OPC .NET) Version 1.00
  • OPC Alarms and Events (OPC AE) Version 1.10
  • OPC Data Access (OPC DA) Versions 1.0a, 2.0, 2.05a, and 3.0
  • OPC Unified Architecture (OPC UA) Clients
  • SuiteLink and FastDDE for Wonderware

Release Notes



  • Fixed an issue that could cause some tags to fail generation during ATG.



  • Fixed an issue that could cause some tags to fail to generate during ATG.



  • Fixed an issue introduced in the 6.5 release, where an extra character could be appended to the end of the value written to string tags.



  • Fixed a rare case where certain data types were not recognized during tag generation.
  • Fixed a possible memory corruption when reading/writing strings.


  • Fixed an issue when writing to a tag within a nested structure would update all tags within the nested structure when writing to a BC/BX device.



  • Fixed a potential buffer overwrite when reading/writing strings.



  • Fixed an issue where writing to a tag within a nested structure would update all tags within the nested structure when writing to a BC/BX device.



  • Fixed an issue with filter items auto-generated incorrectly from a .tpy file.



  • Resolved an issue where memory could be corrupted in certain scenarios when filtering tags.



  • Fixed an issue where automatic tag generation from a *.tpy file would force all characters in the address to be uppercase. The case is now left as is in the *.tpy file.
  • Fixed an issue where generating tags with the option Only import variables marked for OPC enabled would cause the server to become unresponsive after attaching a client.
  • Corrected an issue where nested structures were not always being automatically generated correctly from a TwinCAT device.
  • Corrected an issue where tags automatically generated from a device and from an equivalent *.tpy file would result in non-equivalent projects under certain conditions.



  • Fixed an issue where generating tags with the option "Only import variables marked for OPC" enabled would cause KEPServerEX to become unresponsive after attaching a client.


  • Both a copy of TcAdsDll.dll and the Beckhoff TwinCAT Remote Manager Utility are no longer provided with the install. Users must obtain the TwinCAT ADS Communication Library from Beckhoff in order to access the tools that are required to configure successful AMS Remote Connections.
  • Improved performance reading from TwinCAT 3 PLC by monitoring the OnlineChangeCnt global variable and not reading the symbolic information for every read.



Fixed an issue that was introduced in the 5.3 release when compatibility information was added that affected the reading of OPC Read Only variables.



Fixed an issue where a repeating Event Log message occurred when multiple TwinCAT devices were located on a single channel.


  • Corrected issues that prevented the Port Number device property from persisting in sheet mode.
  • Corrected issues in wizard mode that caused changes to the Port Number to be lost after leaving the page and returning to wizard mode.
  • For TwinCAT PLC models, do not attempt to read device version information if the API dlls are missing (or if generating tags from a symbol file).
  • Optimized communications with TwinCAT PLC models by minimizing the overhead previously put on the device.
  • Automatically generated tags no longer allow clients to override the assigned data type.


  • Added support for TwinCAT PLC version 2.10 with builds 909 or earlier.


  • Removed the pop-up displayed during Automatic Tag Generation (ATG) for arrays with more than 1000 elements.
  • Updated the driver to check each device's version as applicable (instead of assuming that all devices under a channel are using the same Firmware version).
  • Fixed an issue with legacy tag processing where the entire queue would fail if the last tag failed to get symbols.
  • Improved DNR handling with legacy tag processing.
  • Made performance improvements to tag queuing in the state machine. If any step of the tag read or write transaction fails, the tag will fail and be removed from the queue in order to eliminate the need to keep trying the tag. The number of retries is now applied to the entire tag transaction instead of each individual step.


  • Added support for TwinCAT PLC version 2.9. The driver now queries the version information to determine what function codes can be used to communicate with the controller.


  • Fixed issue where the driver was unable to load tags in structures from a .tpy file for a BC/BX device.



  • Fixed anomaly where writes to IO could fail, and reads from IO would not always report the correct values.

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