Normally, when the sequential function chart for an active state completes without error, the phase continues along the defined path to the next state. However, there may be times when you want to force a transition to a particular state. (It must still be along one of the predefined paths.) In such cases, you can use a phase command in your SFC logic.
The main phase commands that are used to transition from one state to another are listed in the table below. These commands can be used in the phase logic. There are equivalent batch commands that an operator can issue to control a batch from the Batch Operator Interface.
| Command | Description |
|---|---|
| Abort | Invokes the aborting logic. Abort is an emergency stop. |
| Hold | Used for a phase in the running or restarting state. Hold invokes the holding logic to temporarily stop the phase and proceed to the held state, from which the Restart command can be used. |
| Reset | Transitions the phase from an aborted, complete, or stopped state to the idle state. |
| Restart | Used for a phase in the held state to invoke the restarting logic. |
| Start | From idle, the Start command invokes the running logic. |
| Stop | Invokes the stopping logic. |