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;
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