Communication State Model¶

1. Overview¶

The Communication State Model defines the states of SECS-II communication between the equipment and host as specified in SEMI E30 (GEM).

2. State Diagram¶

stateDiagram-v2 [*] --> DISABLED state ENABLED { [*] --> NOT_COMMUNICATING NOT_COMMUNICATING --> COMMUNICATING: Communication Established COMMUNICATING --> NOT_COMMUNICATING: Communication Failed } DISABLED --> ENABLED: Enable Communication ENABLED --> DISABLED: Disable Communication

3. State Definitions¶

State	Description
DISABLED	Communication is disabled. Equipment will not accept or initiate SECS-II messages.
ENABLED	Communication is enabled. Equipment is ready to establish communication.
NOT_COMMUNICATING	Communication is enabled but not yet established with host.
COMMUNICATING	Active communication with host. SECS-II messages can be exchanged.

4. Transition Table¶

#	Current State	Trigger	Next State	Action
1	DISABLED	Operator enables communication	ENABLED/NOT_COMMUNICATING	Initialize HSMS, wait for connection
2	NOT_COMMUNICATING	S1F13 received and accepted	COMMUNICATING	Send S1F14 (COMMACK=0)
3	NOT_COMMUNICATING	S1F13 sent and S1F14 received (COMMACK=0)	COMMUNICATING	Communication established
4	COMMUNICATING	Communication failure detected	NOT_COMMUNICATING	Raise alarm, attempt reconnection
5	COMMUNICATING	S1F13 received	COMMUNICATING	Send S1F14 (re-establish)
6	ENABLED	Operator disables communication	DISABLED	Close HSMS connection
7	NOT_COMMUNICATING	T7 timeout (HSMS)	NOT_COMMUNICATING	Disconnect, retry connection

5. Communication Establishment¶

5.1 Host-Initiated Scenario (Primary)¶

sequenceDiagram participant Host participant Equipment Note over Equipment: State: NOT_COMMUNICATING Host->>Equipment: S1F13 (Establish Communication Request) Note over Equipment: Validate request Equipment-->>Host: S1F14 (COMMACK=0) Note over Equipment: State: COMMUNICATING

5.2 Equipment-Initiated Scenario¶

sequenceDiagram participant Host participant Equipment Note over Equipment: State: NOT_COMMUNICATING Equipment->>Host: S1F13 (Establish Communication Request) Host-->>Equipment: S1F14 (COMMACK=0) Note over Equipment: State: COMMUNICATING

Message	Direction	Description
S1F13	H↔E	Establish Communication Request
S1F14	H↔E	Establish Communication Request Acknowledge

6.1 S1F13 - Establish Communication Request¶

Structure:

S1F13 W
<L[0]>

6.2 S1F14 - Establish Communication Request Acknowledge¶

Structure:

S1F14
<L[2]
  <COMMACK>          // Communication acknowledgment code
  <L[2]
    <MDLN>           // Equipment model type
    <SOFTREV>        // Software revision
  >
>

COMMACK Values:

Value	Description
0	Accepted
1	Denied, Try Again

SVID	Name	Type	Description
`[1001]`	CommunicationState	U1	Current communication state (0=Disabled, 1=Enabled-NotComm, 2=Enabled-Comm)

CEID	Name	Description
`[1001]`	CommunicationEstablished	Triggered when entering COMMUNICATING state
`[1002]`	CommunicationDisabled	Triggered when entering DISABLED state
`[1003]`	CommunicationFailed	Triggered when communication is lost

ALID	ALTX	Category	Description
`[1001]`	Communication Lost	Warning	Host communication has been lost