Phase classes > State transition diagrams

Common phase logic parameters

The phase logic starts with a number of default phase parameters, such as BATCH_ID and OWNER. In addition, a unit phase inherits any phase parameters that were created in the phase class. (For example, any unit phase created from the phase class FILL will have the additional phase parameter FILL_AMOUNT.)

Parameter Description
AUTO_RESTART Set by the Batch Executive to instruct all loaded phases whether or not to auto-restart from a holding condition.
BATCH_ID Contains the unique batch ID for the phase at run-time.
BCOMMAND Commands the phase logic to go to a state, as defined by the state transition diagram. This parameter is to be used exclusively by the DeltaV Batch Executive, while the phase owner is DeltaV Batch.

Caution Do not write to this parameter directly as it can cause the Batch Executive to lose control of the phase.

BSTATUS Shows the state of the phase.
FAIL_INDEX

Shows and defines the failure of a phase, where 0 = No Failure and any non-zero integer = Failure. A translation string for a positive integer less than 255 can be created in the phase_failures named set.

Note that the hold logic executes from the first hold step when the FAIL_INDEX changes to a higher value, even when the hold logic is currently running (holding). Therefore, the Phase_Failures named set values should be configured so that the most serious condition has the highest value.

INITIAL_STATE Defines the state that the SFC is in when downloaded (Sequence Active or Sequence Idle). The default is Sequence Active. This parameter is available in the composite block.
OWNER Identifies the control mode, DeltaV Batch or External. When the batch control is External, the parameter controlling the phase transitions is XCOMMAND (instead of BCOMMAND), which allows the user to control the phase.
PROMPT_BOOL Stores the operator response to a prompt requiring a Yes/No response.
PROMPT_INT Stores the operator response to a prompt requiring an integer response.
PROMPT_FLOAT Stores the operator response to a prompt requiring a floating point response.
PROMPT_STRING Stores the operator response to a prompt requiring a string response.
REQDATA1…5 Used to pass request data between the phase logic and the DeltaV Batch Executive.
REQUEST A request to the DeltaV Batch Executive from the phase logic.
STATE_TIME Shows the time (in seconds) the module has been in the current state.
TIME The amount of time the SFC has been running. This is the accumulated time that has passed since the sequence was started.
UNIT Shows the ID of the unit.
WATCHDOG Used to verify communication with the DeltaV Batch Executive. The Batch Executive writes to the Watchdog parameter when the phase state is not Idle and the owner is DeltaV Batch. The phase logic checks the Watchdog parameter every time it executes.
XCOMMAND Commands the phase to go to a particular state, as defined by the state transition diagram. This parameter is used when running the batch externally. See OWNER parameter.