RemoteVariableSynchronizer() constructor

IMPORTANT:

The RemoteVariableSynchronizer allows you to force tags to constantly synchronize with a controller. Constant synchronization is resource-demanding and may significantly impact the performance of a

FactoryTalk Optix Application

and a controller.

Rockwell Automation

recommends that you:

Limit the RemoteVariableSynchronizer usage to a small set of tags. If you need to force read or write a tag in a NetLogic, use IUAVariable.RemoteRead(timeoutMilliseconds) or IUAVariable.RemoteWrite(value, timeoutMilliseconds)instead.

Add timespan as an argument of the constructor to reduce the communication load. If you do not specify the timespan, tags synchronization runs in a continuous loop. As soon as the last tag values is received, a new synchronization cycle begins with no wait time.

Use the RemoteVariableSynchronizer to keep a specific set of tags synchronized with a controller in a NetLogic. For example, use the RemoteVariableSynchronizer to subscribe to a VariableChange event. See Create a subscription.

Tags are automatically synchronized, so you do not need to use the RemoteVariableSynchronizerTags when:

Tags are used in the currently displayed interface

Tags are used in a data logger

A tag is an input variable for an alarm

A tag has a ValueChange event

Create a

RemoteVariableSynchronizer

object that can contain a list of project variables to be kept synchronized with the related field variables.

public RemoteVariableSynchronizer()

IMPORTANT: The

RemoteVariableSynchronizer

object must be declared as a class member within the NetLogic.

Constructor with the default polling time

In the following example, a

variableSynchronizer

object is created to keep the value of a

Speed

project variable synchronized with the value of a field variable that identifies the speed of a motor. The project variable, represented by the

motorSpeed

object, is added to the

variableSynchronizer

object via the

Add()

method.

When the field variable changes its value, the

motorSpeed_VariableChange

method is executed. When the value of

motorSpeed

(of the field variable), is greater than 200, a warning message is generated. The default polling time is set to full speed.

private void Start() {
        motorSpeed = LogicObject.Owner.GetVariable("Speed");
        variableSynchronizer = new RemoteVariableSynchronizer();
        variableSynchronizer.Add(motorSpeed);
        motorSpeed.VariableChange += MotorSpeed_VariableChange;
    }
    private void MotorSpeed_VariableChange(object sender, VariableChangeEventArgs e) {
        if (motorSpeed.Value > 200) {
            Log.Warning("Speed limit reached!");
        }
    }
    private IUAVariable motorSpeed;
    private RemoteVariableSynchronizer variableSynchronizer;

In the

Stop()

method, the end of the synchronization when the NetLogic parent node is removed is caused by invoking the

Dispose()

method.

Constructor with a custom polling time

In the following example, the polling time for

RemoteVariableSynchronizer

is set to

5000

milliseconds.

public override void Start()
{
    var variable1 = Project.Current.Get<IUAVariable>("Model/Variable1");
    variable1.VariableChange += Variable1_VariableChange;

    synchronizer = new RemoteVariableSynchronizer(TimeSpan.FromMilliseconds(5000));
    synchronizer.Add(variable1);
}

private void Variable1_VariableChange(object sender, VariableChangeEventArgs e)
{
    Log.Info($"Variable1 {e.NewValue}");
}

public override void Stop()
{
    synchronizer.Dispose();

    var variable1 = Project.Current.Get<IUAVariable>("Model/Variable1");
    variable1.VariableChange -= Variable1_VariableChange;
}

RemoteVariableSynchronizer synchronizer;

Keep field variables synchronized

Provide Feedback

Have questions or feedback about this documentation? Please submit your feedback here.