State Models
There are two types of state models in the AdeptGEM system:
- Models that are required by the SEMI standards and are a basic part of the AdeptGEM module.
- State models that you design and implement as part of an executing sequence.
SEMI Required State Models
There are three required state models:
- The communication state model is described in Establish Communications (detailed in Table 3.2 in SEMI E30).
- The control state model is described in Control (Host-Initiated) (detailed in Table 3.3 in SEMI E30).
- The equipment processing state model is described in Equipment Processing State Model.
There are three descriptive elements for a state model: The description of states that the equipment can be in; the description of events that can trigger changes in equipment states; and the description of the transitions that occur when an event triggers a state change. In order to generate your own state model you will describe all of these events (normally using the descriptive tools described in SEMI E30, section 3). You then create the AIM sequence that implements the state model. The sequence will use State records to describe the various events that are triggered by state transitions.
You can make your own state model as follows:
Define a state variable (in the GEM Variables database) to be used to store a "current" state value. (This variable will be a status variable that can be "seen" by the host through a collection event, status data collection, etc.)
Define various states (in State records in the GEM Items database) for the above variable. "Actions" can be associated with these states that are automatically performed upon a transition to the state. Actions include any combination of the following (the associated menu-page fields are shown):
Define state transitions by including in an AIM sequence SET_STATE statements that change the state as the sequence is executed.
Refer to the SET_STATE statement and the State Record Type for details.
State Model Example
The following example shows a possible user-defined state model in action.
The defined state variable (in the GEM Variables database) is ProcessMode.
Its possible states (defined by State records in the GEM Items database) are: Action and Analysis.
- A transition to Action state may imply that the part has been removed from the inspection table.
- A transition to Analysis state may imply that a part has been placed on an inspection table.
A possible AIM sequence might be:
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See Introduction to AdeptGEM Statements for details on the statements added by the AdeptGEM module.