Beckhoff ADS Listener

Description

Beckhoff ADS Listener is used for listening to Beckhoff TwinCAT value changes using ADS protocol.

note

For using Beckhoff ADS channels you need to put the AdsToJava-3.dll in a folder and start the Orchestra applications with this argument -Djava.library.path=<Path to the DLL folder> .

Creation

To create an Beckhoff ADS Listener, follow the steps described in the general description of Channels.

Configuration

The dialog to configure the Beckhoff ADS Listener looks like:

Base view of the Beckhoff ADS Listener

• Beckhoff ADS Connection is the connection to Beckhoff TwinCAT

• Notification Mode is the triggering condition of the notification

Notification Mode	Description
Fire event when the data changes	Notifies only when the variable value changes.
Fire event cyclically	Notifies cyclically based on the PLC’s internal task cycle.
Gets cyclically updates and fire event when data changes	Gets cyclic updates but only notifies if the value has changed compared to the last value.
Client triggered cyclic notification event	Notifies cyclically at the interval specified by the client.

• Max. delay (ns) is maximal delay in nanoseconds

• Cycle time (ns) is the cycle time of the notification in nanoseconds

Notification variables

• Variable is the name of the variable to notify <class name>.<variable name>

• Data type is the data type of the variable

• Is array needs to be set true if the variable is an array.

• Array length the array length. Can only be set if Is array is true.

• String length the string length. Can only be set if Is array is true and Data type is STRING.

Notification Message

The ADS notification message type:

Message type of Beckhoff ADS Lister notification

• value: the value
• timeStamp: The timestamp when the message was created
• variable: the variable name
• dataType: data type of the variable. As data type name, all type names found in the TwinCAT can be used here.

Example

<?xml version="1.0" encoding="UTF-8"?>
<AdsNotification>
	<value dataType="STRING" timeStamp="Fri Apr 11 10:34:18 CEST 2025" variable="MAIN.stringVar">Hello World</value>
</AdsNotification>