Control site: Asynchronous validation

Asynchronous Validation enables RCO to wait for one or more Validation points while continuing to execute additional control cycles. This means that when a control cycle is in progress, the control site can be triggered (to start a new control cycle) while waiting for the Verification point to set and to mark the decision 'Complete'.


Each asynchronous validation decision has two additional fields: Validation point and Default validation value.

  1. The Validation Point must be set to the Validation value in order for the decision to be considered complete.

  2. RCO will continue to execute control cycles while waiting for validation to occur.

  3. When the logic module has selected a decision, the

  1. Output modules will run and

  2. Decision will appear in the RCO_UI as Pending.

  1. If the decision has a Validation Point configured:

  1. The site will wait for the validation, and process any additional triggers.

  2. The decision waiting for validation will be marked as InProcess until the Verification.

  1. RCO maintains a history of the last 32 decisions.

  1. When a new decision is made, it is added to the decision history.

  2. When the maximum number of configured decisions is exceeded, the oldest decision is removed from the list.

  1. RCO triggers an alarm if a decision is removed and was not validated.

  2. Once a decision has been removed from the list, it is considered canceled.

Decision Complete

  1. When Async Validation is configured for a decision and the default value is specified in the Decisions dialog box or in the Output Module via the Set Asynch Validation Value function block, the decision status reads, InProcess.

  2. When RCO receives a Point update whose value is equal to the configured Validation Point, the decision is then marked 'Completed'.

 Configuration Guidelines: When configuring Decisions for an RCO, set the Validation Point and designate a value in the Val. Point Value field. If these fields are not configured, the decision will not wait for a validation Point to be updated, and the decision will be marked as complete at the end of the cycle.

Use the Set Async Validation Value function block to change the default value for a particular cycle. You can assign the value or tie it to a variable. Configure this function block in the output module only. Note that if the default value is not configured in the Decisions dialog box, but is configured in the output module using the above-mentioned function block, the decision will wait for the validation Point to be updated with the value assigned in the function block for completion.

The site must have a thread available for performing async validation. Set the thread count accordingly in its folder's properties.

More information

1. RCO Control Site.