1

Create a sender and a receiver controller in the Devices tree.

2

Create a program (POU) for the sender and receiver controller.

3

Add a task for the sender and receiver controller.

NOTE: In order to maintain performance transparency, you should set the task priority of the dedicated NVL task to something greater than 25, and regulate communications to avoid saturating the network unnecessarily.

4

Define the NVL (sender) for the sender.

5

Define the NVL (receiver) for the receiver.

Network type

UDP

Only the network type UDP is available.

To change the Broadcast Address and the Port, click the Settings... button.

Task

MAST

Select the task you configured below the Task Configuration item for executing NVL code.

To help maintain performance transparency, it is a good practice configure a cycle time Interval ≥50 ms for this task.

NOTE: In order to maintain performance transparency, you should set the task priority of the dedicated NVL task to something greater than 25, and regulate communications to avoid saturating the network unnecessarily.

List identifier

1

Enter a unique number for each NVL (sender) on the network. It is used by the receivers for identifying the variables list.

Pack variables

activated

With this option activated, the variables are bundled in packets (datagrams) for transmission.

If this option is deactivated, one packet per variable is transmitted.

Transmit checksum

deactivated

Activate this option to add a checksum to each packet of variables during transmission.

Receivers will then check the checksum of each packet they receive and will reject those with a non-matching checksum. A notification will be issued with the NetVarError_CHECKSUM parameter.

Acknowledgement

deactivated

Activate this option to prompt the receiver to send an acknowledgement message for each data packet it receives.

A notification will be issued with the NetVarError_ACKNOWLEDGE parameter if the sender does not receive this acknowledgement message from the receiver before it sends the next data packet.

Cyclic transmission

oInterval

activated

Select this option for cyclic data transmission at the defined Interval.

This Interval should be a multiple of the cycle time you defined in the task for executing NVL code to achieve a precise transmission time of the network variables.

Transmit on change

oMinimum gap

deactivated

oT#20ms

Select this option to transmit variables whenever their values have changed.

NOTE: After the first download or using of Reset Cold or Reset Warm command in Online Mode the receiver controllers are not updated and keep their last value, whereas the sender controller value becomes 0 (zero).

The Minimum gap parameter defines a minimum time span that has to elapse between the data transfer.

Transmit on event

oVariable

deactivated

o–

Select this option to transmit variables as long as the specified Variable equals TRUE. The variable is checked with every cycle of the task for executing NVL code.

Port

1202

Enter a unique port number (≥ 1202) for each NVL (sender).

Broadcast Address

255.255.255.255

Enter a specific broadcast IP address for your application.

Name

NVL

Enter a name for the NVL (receiver).

Task

task defined in the Task Configuration node of this Application

Select a task from the list of tasks which will receive the frames from the sender that are available under the Task Configuration node of the receiver controller.

Sender

1 of the NVL (sender) available in the project

Select the NVL (sender) from the list of the NVL (sender) with network properties available in the project.

Select the entry Import from file from the list to use an NVL (sender) from another project. This activates the Import from file: parameter below.

Import from file:

–

This parameter is only available after you selected the option Import from file for the parameter Sender.

The ... opens a Windows Explorer window that allows you to browse to the export file *.gvl you created from an NVL (sender) in another project.

For further information, refer to the How to Add an NVL (Receiver) From a Different Project paragraph below.