Description
Product description
In addition to client/server communication , communication via the OPC UA Pub/Sub protocol provides another option for exchanging data between network participants in accordance with the rules of the OPC UA Foundation . The structure of the data ( ) can be freely defined and is agreed upon in advance between sender and receiver. This eliminates the need to transport additional (meta) data. Data is transferred using the OPC UA PubSub SL library via UDP/IP according to the rules defined for UADP . A so-called publisher publishes its data to an unknown number of subscribers . The sender and receiver do not know each other. The number of recipients therefore has no effect on the sender. In principle, the protocol cannot provide feedback to the sender as to whether its messages have reached the recipient. If required, such feedback must be managed on an application-specific basis. The data is transmitted in a binary format in accordance with the rules of the OPC UA Foundation . The OPC UA PubSub SL library converts the IEC data types into the corresponding OPC UA data types and vice versa . The implementation follows the following profiles:DataSet
- Publisher: PubSub Publisher UADP Periodic Fixed Settings
- Subscriber: PubSub Subscriber UADP Periodic Fixed Settings
The length of the messages is limited to 1500 bytes (MTU) ( Chunked NetworkMessages not supported ). As long as the rules for a time-sensitive network are not yet available, hard real-time conditions cannot be met. However, the implementation of the OPC UA PubSub SL library tries to keep the jitter as low as possible.
Requirements
| Programming system | CODESYS Development System V3.5.17.0 or higher |
| Runtime system | CODESYS Control V3.5.14.0 or higher |
| Supported platforms/devices | Note: Use the Device Reader project to determine the functions supported by the controller. Device Reader is available free of charge from the CODESYS Store. |
| Additional requirements | Depending on the equipment of the respective runtime system, the messages can be sent via unicast , multicast or broadcast . |
| restrictions | The maximum length of a network message is 1500 bytes ( Chunked NetworkMessages not supported ) |
| Licensing |  Single device license: The license can be used on the controller on which the CODESYS runtime system is installed.
The license is activated on a software-based license container (soft container) that is permanently linked to the controller. Alternatively, the license can be stored on a CODESYS key (USB dongle). The license can be used on another controller by replugging the CODESYS key. Note: Without a license, the software runs in demo mode for 30 minutes. After that, a manual restart is required. |
| Required accessories | – |
