Be sure to verify your downloads by these procedures using these KEYS for any Apache release.

Current Releases

0.12.0 Official source release [ SHA512 ] [ ASC ]

This release was mainly a release containing many bugfixes. We literally halved the number of open issues. A second major topic would have been another API streamlining in preparation to aiming for the big 1.0.0 release. The API was extended by additional features, that now allow tools to automatically provide support for tool assist when connecting to devices. Now additional information such as: - Which transports does a given driver support? - Which is the default transport for a given driver? - Which configuration-options does a driver have? - What types are these configuration options? - What are the default-values these configuration options have? - Which of these configuration options are required? - The same set of information is also available for the transports a driver is using.

New Features
  • API: Made several bits of information available via the API allowing tools to provide more content assist when dealing with PLC4X connections.

  • S7: The S7 driver now supports reading of STRING and WSTRING data-types without providing a maximum length.

  • Build: Worked on making PLC4X provide reproducible builds.

  • Added "Ping" functionality to: ADS, EIP, KNX, Mock, Modbus and Simulated drivers.

  • The OPC-UA Java driver now support certificate-based authentication and encryption.

Incompatible changes
  • Java 8 is no longer officially supported and Java 11 is the new base-line.

  • Renamed the PlcDriverManager method listDrivers to getProtocolCodes

  • Renamed the PlcDriverMetadata method canDiscover to isDiscoverySupported

  • Renamed the PlcConnectionMetadata methods canRead, canWrite canSubscribe and canBrowse to isReadSupported, isWriteSupported, isSubscribeSupported and isBrowseSupported

  • The configuration syntax for configuring transport-related config options in the connection-string was updated to be now prefixed with the transport name the option belongs to.

Bug Fixes
  • S7: Several bugs and issues regarding supporting various duration, date and time data-types.

  • S7: Implemented the missing 64bit (L-) types.

  • KNX: Fixed an issue with decoding 16 bit floating point numbers.

  • NiFi-Integration: The NiFi integration module was greatly improved.

  • Core: Fixed several leaks of open threads.

Previous Releases

0.11.0 Official source release [ SHA512 ] [ ASC ]

The APIs have been streamlined in a preparation for a hopefully soon 1.0.0 release. Many drivers have been re-implemented with much more features. Integration modules have been improved.

New Features
  • Implemented a PLC4X-Server and PLC4X-Driver that allows using the server as a proxy for communicating with PLCs.

  • The Modbus driver is now also available in the variants: "modbus-rtu" and "modbus-ascii" (Both using Serial communication, which however can be tunneled through a "tcp" and "udp" transport)

  • The KNX driver in Java now supports reading "knxproj" files exported from the new ETS version 6.

Bug Fixes
  • The name of the Modbus TCP driver was changed from "modbus" to "modbus-tcp".

  • Removed the Apache Edgent (incubating) integration and examples related, as Edgent is abandoned and there were CVEs reported, which will not be fixed.

  • We have replaced the BitString types with BYTE, WORD, DWORD, and LWORD which generally match their unsigned integer counterparts. So we are no longer returning lists of boolean values for any of these types.

0.10.0 Official source release [ SHA512 ] [ ASC ]

A lot of the work in this version went into refactoring and cleaning up our code generation. The code generation itself is now a lot cleaner and simpler as well as the code generated for Java. We also added a number of new field-types to allow implementing more sophisticated protocols. PLC4C now should also support all of the constructs mspec has to offer.

0.9.1 Official source release [ SHA512 ] [ ASC ]

This is a bugfix release aiming at directly fixing CVE-2021-43083 as well as updating the dependency to Log4J 2.14.0 which was affected by CVE-2021-44228

Please note that CVE-2021-43083 only affects the PLC4C part of PLC4X.

Bug Fixes

CVE-2021-43083 Apache PLC4X 0.9.0 Buffer overflow in PLC4C via crafted server response

0.9.0 Official source release [ SHA512 ] [ ASC ]

This is an ordinary PLC4X release, containing changes that accumulated over time. It doesn’t have an explicit focus on a particular topic.

New Features
  • The OPC UA driver has been replaced with a native driver. Previously Eclipse Milo was being used.

  • Permit customized package names for code generation

  • Added an initial draft of a Discover and Browse API to PLC4J

  • PLC4Go now supports many more drivers

  • PLC4Go received a huge internal refactoring and cleanup

  • Major cleanup of PLC4C

  • S7 Driver now supports event and alarm handling on some S7 models

Incompatible changes
Bug Fixes

PLC4X-200 OPC-UA Driver not connecting if params string is not provided PLC4X-201 OPC-UA PlcList underlying type not compatible with Eclipse Milo PLC4X-202 OPC-UA Driver cannot write Unsigned Types PLC4X-276 [S7] The most of the supported types don’t work correctly PLC4X-278 Double Reading Error PLC4X-279 nioEventLoopGroup thread proliferation PLC4X-280 ADS route request swapped positions of route name and address PLC4X-291 DefaultPlcSubscriptionField cannot be cast to class OpcuaField PLC4X-298 [S7] When writing REAL values the Write operation fails with an internal error PLC4X-299 Modbus - Kafka Connect Configuration PLC4X-312 CAN NOT READ STRING FROM S7 PLC PLC4X-314 CAN NOT WRITING MANY DATA TO S7 ONE TIME

0.8.0 Official source release [ SHA512 ] [ ASC ]

This is an ordinary PLC4X release, containing changes that accumulated over time. It doesn’t have an explicit focus on a particular topic.

New Features
  • The KNXnet/IP Driver now supports writing of values.

  • The Modbus driver now supports more common notations of Modbus addresses using a pure-numeric notation.

  • The ADS, KNX, Modbus, S7 and simulated drivers have been updated to support the IEC 61131-3 data-types.

  • We are now including PLC4Go as PLC4X implementation in the programming language Go(lang)

  • Integration with the Milo OPC UA Server is now available.

  • Kafka Connect workers have been updated source and sink connectors are now included.

Incompatible changes
  • The syntax of the S7 addresses changed slightly allowing to provide a string length. Without this, a STRING datatype will read 254 characters, by adding the size in round brackets to the type name will use the specified number.

    Read one String which is max 10 chars long:
    Read an array of 3 Strings where each is max 10 chars long:
  • The PLCValue types have been refactored to align with the types defined in IEC 61131-3 ( directly using the older Java types (PlcBoolean) is no longer possible.

Bug Fixes

A lot of testing was done regarding the IEC 61131-3 data-types. This resulted in numerous bugfixes in many protocols.

  • PLC4X-132 [S7] Communication to S7 PLC dies in some situations

  • PLC4X-206 When writing short values exceptions are thrown while preparing the write request.

  • PLC4X-207 No registered handler found for message TPKTPacket[], using default decode method - Communication with S7 and Modbus device hangs

  • PLC4X-209 [S7] When writing INT and DINT values the Write operation fails with an internal error

  • PLC4X-210 [KNX] When running a KNX Tunneling Subscription for a longer time there are packets that kill the connection

  • PLC4X-211 PlcValues seem to always return "true" on the isXYZ" checks.

  • PLC4X-212 When writing multiple values in one request the item status is not correctly set

  • PLC4X-213 [Modbus] The Modbus driver doesn’t handle error responses gracefully

  • PLC4X-214 [Modbus] Holding register addresses have an offset of 1 (Not reading the correct address)

  • PLC4X-215 Drivers using the BaseOptimizer (SingleFieldOptimizer) don’t handle error responses gracefully

  • PLC4X-218 [Scraper] After stopping the scraper still the statistics are logged and the application doesn’t terminate

  • PLC4X-239 Read DTL (Date and Time)

  • PLC4X-240 Protocol error in reading string

  • PLC4X-246 S7 driver hangs on read

  • PLC4X-245 [Modbus] Apache NiFi processor throws after a while

  • PLC4X-255 Kafka Connector Source Task doesn’t block within poll() resulting in high CPU usage.

  • PLC4X-261 Pooled connection manager returns a connection that isn’t connected in some situations.

  • PLC4X-272 When splitting up large requests, too big sub-requests are generated (S7)

  • PLC4X-256 ReadBuffer truncate last byte of even small payloads

  • PLC4X-262 Error in reading Array

  • PLC4X-270 Ads driver does not accept double-digit array indexes

0.7.0 Official source release [ SHA512 ] [ ASC ]

This version is the first after a major refactoring of the driver core. All previous driver versions are now considered deprecated and have been replaced by versions using the new driver structure and generated driver codebase.

New Features
  • Drivers now support structured types using PlcValues

  • The EIP (EtherNet/IP) driver no longer requires an external library and is implemented fully in the PLC4X project

  • The Modbus driver no longer requires an external library and is implemented fully in the PLC4X project

  • The new S7 Driver supports writing multiple entries in one request (The API allowed this from the beginning now not every item is wrapped in a single request. It should bring significant performance gains when writing multiple vlaues)

  • S7 Driver now supports String datatypes.

  • OSGi : Implementation of Drivers/Transports as OSGi services to be able to use them in an OSGi container.

  • New Firmata protocol driver

Incompatible changes
  • Due to the refactoring of the driver core there might be issues running drivers built against older core versions.

  • This version doesn’t provide a Beckhoff AMS/ADS driver as this driver is still being ported to the new mspec format.

  • All drivers connection strings now follow the same pattern: {protocol-code:(transport-code:)?//{transport-config}(?{params})? Please check the drivers documentation on our website:

  • The karaf-feature modules are removed as the drivers now all provide both a feature.xml as well as a kar bundled archive

Bug Fixes
  • PLC4X-174 UDP Transport does not accept ports containing 0

  • PLC4X-134 S7 is terminating the connection during handshake

  • PLC4X-192 Support for conversion of complex connection string parameters

0.6.0 Official source release [ SHA512 ] [ ASC ]

This is the last release of PLC4X with the "handwritten" drivers. This Minor release will thus receive updates and fixes until most users have switched to 0.7 and above (with generated drivers).

If you are using the S7 Driver you should update to this Version as the critical (memory leak) bug PLC4X-163 is fixed.

New Features
  • PLC4X-168 A shorter S7 Field Syntax is Introduced. This release contains no further features and mostly stabilization.

Incompatible changes
  • Moved the C++, C# and Python drivers into the sandbox

Bug Fixes
  • Fixed Promise Chain for InternalPlcWriteRequest

  • PLC4X-45 Add float support to Modbus Protocol

  • PLC4X-164 Fix wrong NOT FOUND exception in OPC UA Driver

  • PLC4X-166 Fixed Download Page

  • PLC4X-163 Fixed Netty ByteBuf Leaks for S7 Driver

  • PLC4X-158 Added Warning if no Pooled Driver is used for Scraper

0.5.0 Official source release [ SHA512 ] [ ASC ]

This is the first release containing our new generated drivers (AB-ETH)

New Features
  • Implemented a new Apache Kafka Connect integration module

  • Implemented a new Apache NiFi integration module

  • Implemented a new Logstash integration module

  • Implemented a driver for the AB-ETH protocol

  • Implemented Apache Karaf features for S7 OSGI drivers

  • PLC4X-121 Develop Code Generation to allow Generated Drivers in multiple Languages

Sandbox (Beta-Features) - Implemented a new BACnet/IP passive mode driver - Implemented a new Serial DF1 driver

Incompatible changes
Bug Fixes
  • PLC4X-104 S7 Driver Datatype TIME_OF_DAY causes ArrayOutOfBoundException

  • PLC4X-134 S7 is terminating the connection during handshake

  • PLC4X-139 PLC4X leaks sockets in case of connection problems

  • PLC4X-141 String with real length of greater 127 throw an exception

  • PLC4X-144 When requesting invalid addresses, the DefaultS7MessageProcessor produces errors

0.4.0 Official source release [ SHA512 ] [ ASC ]

This is the first release of Apache PLC4X as top-level project.

New Features
  • The PlcConnection now supports a ping method to allow checking if an existing connection is still alive.

  • Support of the OPC-UA protocol with the opc-ua-driver.

  • Other Languages Support: — Added first versions of a C# .Net PLC4X API (plc4net) — Added first versions of a Python PLC4X API (plc4py)

  • Added an Interop server which allows to relay requests from other languages to a Java Server

Incompatible changes
  • ElasticSearch example was updated to use ElasticSearch 7.0.1, this might cause problems with older Kibana versions.

Bug Fixes

Incubating Releases

0.3.1 (incubating) Official source release [ SHA512 ] [ ASC ]

New Features
  • No new features

Incompatible changes
  • No incompatible changes.

Bug Fixes
  • The S7 driver didn’t correctly handle "fill-bytes" in multi-item read-responses and multi-item write-requests

  • Fixed NPE when reading odd-length array of one-byte base types

  • Renamed flags "F" to Siemens Standard "M" (Marker)

  • Fixed a bug in the DefaultS7MessageProcessor which didn’t correctly merge together split up items

0.3.0 (incubating) Official source release [ SHA512 ] [ ASC ]

New Features
  • Object PLC Mapping (OPM) now has a Alias Registry to allow variable substitution at runtime and write support

  • New module plc-scraper for applications that have to scrape a lot of sps fields with high frequency

  • New integration apache-karaf to enable plc4j in a karaf runtime environment

Incompatible changes
  • The 'plc4j-core' module has been merged into 'plc4j-api'. So there is no 'plc4j-core' module anymore. Just remove that dependency.

  • The driver artifact names have changed so if you were using a plc4j-protocol-{name} you now need to change this to plc4j-driver-{name}

Bug Fixes
  • Fixing dependency to the wrap url-handler

  • When receiving responses with more than 512 byte, the IsoOnTcp protocol doesn’t work

  • When the last item in a request is a DINT, the DefaultS7MessageProcessor dies

  • Write operations seem to fail

  • Fixed a Bug where S7 was not able to read arrays.

0.2.0 (incubating) Official source release [ SHA512 ] [ ASC ]

  • Changed API: instead of passing request object to read({read-request}), write({write-request}) or subscribe({subscribe-request}) methods now the execute() method is called on the request itself

  • New Connection Pool component

  • New OPM (Object PLC Mapping) component (JPA for PLCs)

  • Bug fixes

0.1.0 (incubating) Official source release [ SHA512 ] [ ASC ]