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SEMI E30-1103 © SEMI 1992, 2003 85 Table A .3 Alarm Example s Per Equipment Configuration Subsystem Alarm Description ALID Trigge r Reset Operator Equipment Material Mainframe Power Supply Overvoltage Voltage supply over…

SEMI E30-1103 © SEMI 1992, 2003

The host configures the equipment to monitor specific

variables and to send event reports when variables

transition between monitoring zones.

A1.4 Processing

A1.4.1 Start Process Executing  The host or

operator issues a command to start.

A1.4.2 Equipment Signals End of Run  When

process execution is completed, the equipment

generates events. If any of the events are enabled, they

will be sent as event reports.

A1.5 Post-Processing  The equipment has

completed processing material. It now makes the

material available to the operator or material handling

system for removal. The equipment signals the host that

it is available for more work.

A1.5.1 Material Unload  Material is unloaded from

the equipment by an operator or material handling

system.

A.2 Equipment Front Panel

In the GEM standard, several requirements are stated

that involve the display or input of information at the

equipment front panel. The “equipment front panel”

refers to an area on the equipment that is available to

the operator under normal use (i.e., without removing

maintenance access panels). This may include a CRT

display, keyboard, switches, and lights.

This application note provides some guidance for

implementation of the GEM front panel capabilities. All

of these requirements map directly to state models and

capabilities defined in Sections 3 and 4. All capabilities

may be implemented in either hardware (buttons,

switches, lights) or in a software/CRT equivalent.

A2.1 Displays and Indicators  The intent of various

displays is to inform the operator of either the current

state of the equipment or of a recent change of state (or

both). Therefore, it is most useful if these displays are

continuously visible and easily recognized at a distance.

Required displays/indicators include:

Communications State: This means that three distinct

states must be represented: DISABLED,

ENABLED/NOT COMMUNICATING, and

ENABLED/COMMUNICATING.

Terminal Services: An “New Host Message” indicator

must be supplied.

A2.2 Switches/Buttons  Note that discrete switches

also contain information for the user. However, these

tend to represent the desired states of the operator/user.

The equipment’s response to a change of a switch may

not be instantaneous. Still, the current position of

switches should be available to the operator.

It may be appropriate to limit the access to some

switches and buttons. This might be done via any of the

standard methods, keys, passwords, combinations, etc.

This is especially true for system default switches that

would not often be changed. Required switches/buttons

include:

Communications State System Default: In what

communications state should the equipment be when

system initialization is complete? The choices are

DISABLED and ENABLED.

Communications State Selector: This is a toggle or

button that will initiate a transition from ENABLED to

DISABLED or vice versa.

Message Recognition Button: This button is used to

initiate an event message to the host which indicates

that the “New Host Message” has been read. This

button should function only when the New Host

Message Indicator is activated and when the received

message is displayed in the terminal display.

A.3 Examples of Equipment Alarms

Table A.3 provides alarm examples pertaining to

various configurational aspects of equipment.

NOTE: It is important to stress that these are just

examples intended to illustrate that alarms pertain to

situations in which there exists a potential for

exceeding physical safety limits associated with people,

equipment, and material being processed as per the

GEM definition of an alarm.

NOTE: The alarm capability is intended as an addition

to standard safety alarms (e.g., lights, horns). There is

no intent to replace direct operator reaction to such

problems. Nor is there the expectation that the host can

necessarily prevent or directly address such alarms.

An actual machine shall have an associated set of

alarms defined by the manufacturer that pertains to its

specific configuration and design. The equipment

manufacturer is responsible for supplying

documentation associated with these alarm definitions.

SEMI E30-1103 © SEMI 1992, 2003

Table A.3 Alarm Examples Per Equipment Configuration

Subsystem Alarm Description ALID Trigger Reset Operator Equipment Material

Mainframe Power

Supply

Overvoltage Voltage supply over

maximum limit

Undervoltage Voltage supply under

minimum limit

Internal Power

Distribution Bus

AC Low AC under minimum

limit

X X

Cooling System Overtemp Temperature over

maximum

X X

Pressure Low Pressure below

minimum

Subsystem The subsystem of the equipment to which the alarm is related

Alarm Description Description of the alarm

ALID The Alarm ID as specified by SECS-II

Trigger Text description of what caused the alarm

Reset Description of how to resolve the alarm condition

Affected Who or what is affected by the alarm trigger: Operator, Equipment, and Material

A.4 Trace Data Collection Example

This example shows an implementation of the Trace

Data Collection capability defined in Section 4.2.3.

S2,F23 sent by host:

TRID = ABCD

DSPER = 000100 (One minute per

period)

TOTSMP = 9

REPGSZ = 3

SVID1 = Temperature

SVID2 = Relative humidity

S6,F1 looks like this (starting at time 1 a.m.):

1st transmission <L,4>

1. ABCD (trace ID)

2. 3 (last sample of the

transmission)

3. 88 5 01 01 03 00

Year Month Day Hour Min Sec

4. <L, n> n = 2 SVID‘s x REPGSZ of

3 = 2 x 3 = 6

72 (temperature)

0.29 (relative humidity)

73 (temp.)

0.30 (r.h.)

71 (temp.)

0.30 (r.h.)

2nd transmission <L,4>

1. ABCD

2. 6

3. 88 05 01 01 06

hr min

4. <L,6>

0.31

0.32

0.31

3rd and last transmission <L,4>

1. ABCD

2. 9

3. 88 05 01 01 09

hr min

4. <L,6>

0.30

0.31

A.5 Harel Notation

Harel’s statecharts extend traditional state-transition

diagrams with several additional concepts, most

important of which are hierarchy and concurrence.

Statecharts depict the behavior of a system by showing

states it may take, events that prompt a change of state,

and the composition of states. What follows is a very

brief description of the symbols defined for use and

how these are useful to describe a system. See Figure

A.5.1 for the basic notational symbols.

Figure A.5.1

Harel Statechart Symbols

States are represented by rounded boxes. A state

transition is shown graphically with a line from the old

state terminating with the arrow symbol at the new

state. Transitions are unidirectional-while the reverse

transition may be possible, it is considered a different

transition with different conditions for initiation and

different resultant actions.

States may be subdivided into substates to facilitate

more concise definition of behavior. Thus, a hierarchy

is defined whereby any state may be a substate of some

parent state and in turn be the parent of its own

substates. Substates must be one of two types, termed

AND substates and OR substates.

A parent maybe divided into two or more OR substates

of which one and only one is the active substate at any

time. The accepted term for this exclusivity is XOR.

Figure A.5.2 gives an example of a simple case of OR

substates. In this example, some system (perhaps a

motor) has a state named FUNCTIONAL. When the

motor is FUNCTIONAL, it may be either ON or OFF,

but never both.

Figure A.5.2

Example of OR Substates

Another way of dividing a parent state corresponds

roughly to subsystems. These AND substates represent

parallelism, such that every AND substate of an active

parent state is considered active. Harel also uses the

term “Orthogonal Component” to refer to AND

substates. However, these parallel substates tend to be

highly interactive and interdependent. For this reason,

the word orthogonal is considered confusing and has

been excluded from use in this document. Figure A.5.3

shows an example of AND substates representing (in

part) an automobile. Note the convention of attaching

the name of the parent state AUTOMOBILE to the

outside of the state in a small box. The substates shown

are independent components and may have their own

substates (of either the AND or OR type):

— LIGHTS may be ON or OFF;

— DOOR may be OPEN or CLOSED;

— ENGINE is constructed of components such as

pumps, pistons, carburetor, etc.

Exiting one of a set of AND substates requires the exit

of all others. In some cases, a transition arrow will be

shown from only one of the substates with the others

implied.