vykonPro-RotationalLoadSequencerV1

RotationalLoadSequencerV1 provides lead-lag control of from 2 to 10 BooleanWritables based upon a fixed sequence. The number of active loads is determined by the Schedule and Required Loads inputs.

RotationalLoadSequencerV1 is available in the HVAC folder of the vykonPro palette

Setup of the object involves the following properties, as follows:

Properties

Actions

Operation

When the Schedule value changes from false to true, the RLSV1 attempts to start the number of loads specified by the Required Loads value. When a load is started the RLSV1 changes the applicable OutX (where X = A-J) to true and starts a timer using the Feedback Delay value. When the timer expires, the RLSV1 evalutes whether the applicable OutX is true and the matching FeedbackX is true. If the FeedbackX is false the load is considered failed and the RLSV1 attempts to start the next load in the rotation order. If the FeedbackX for a running load changes from true to false after the feedback timer period has expired, the RLSV1 considers the load failed while running and attempts to start the next load in the rotation order.

When the RLSV1 evaluates that a load has failed it sets the alarm status bit for the applicable OutX slot and changes the Load Failed to true. The failed load OutX slot value remains true even though additional loads may be started to compensate for the failed load, unless the Stop Failed Load is false in which case the OutX value is changed to false. A failed load with OutX slot status alarm bit set is not considered to be running even though the physical piece of equipment might be running.

The RLSV1 behavior is different than the RLS behavior regarding failed loads. With the RLSV1 once a load has failed regardless of the Stop Failed Load property value, the load is removed from rotation until a user invokes the Reset Failed Load action and selects the applicable OutX to restore the load to operation. The design is such that when a load has failed it should not be used to prevent damage or equipment cycling until the root cause is determined and corrected.

If the RLSV1 has started all available loads and the number of running loads (OutX true and status OK, and FeedbackX true) is less than the Required Loads, the Status is set to Fault and the Fault Cause is updated to indicate 'Not enough loads available to start the required number of loads.

When the Schedule value changes from true to false, the RLSV1 stops all of the outputs (changes all OutX slots to false), but it does not clear the alarm status bit from any previously failed loads. The RLSV1 component will not attempt to use the previously failed loads when the Schedule changes from false to true subsequently.