A batch mode is a state associated with each step of a batch, with rules that apply up and down the recipe hierarchy. Active steps of a recipe are in one of three modes:
However, the DeltaV system lets operators control the mode of steps at each level with only two command buttons:
The following paragraphs give the characteristics of each mode and the way to arrive at each mode:
MANUAL - Placing a step in MANUAL mode puts the selected step and each level of the recipe hierarchy above the selected step in MANUAL mode. Subordinate steps are placed in O-AUTO mode. No command buttons are enabled for a step in MANUAL mode. However, the step must be in MANUAL mode to perform an active step change to the subordinate steps.
O-AUTO - The steps subordinate to a step in MANUAL mode are placed in O-AUTO (operator automatic) mode. Command buttons are active for steps in O-AUTO mode, unless the step has reached a terminal state. All steps subordinate to a step in O-AUTO mode are in P-AUTO mode.
P-AUTO - Steps in P-AUTO (program automatic) mode are under program control and cannot be modified directly by the operator. Command buttons are not enabled. The top level of a recipe is never in P-AUTO mode.
You can consider the batch mode as the mode of the top level of the batch. If the mode is not automatic (that is, O-AUTO or P-AUTO), the batch will not complete automatically. Note, however, that even though the top level is running manually, subordinate parts of the batch may be running automatically. All automatic action is stopped only if all active operations are selected and set to MANUAL.