SECS-II Message Format
Understanding SEMI E5 SECS-II message structure and data types.
What is SECS-II?
SECS-II (SEMI Equipment Communications Standard 2) defines the message format for communication between host systems and semiconductor manufacturing equipment.
Message Structure
Stream Function (SxFy)
├── Header (10 bytes)
│ ├── Device ID (2 bytes)
│ ├── Stream (1 byte)
│ ├── Function (1 byte)
│ ├── P-Type (1 byte)
│ ├── S-Type (1 byte)
│ └── System Bytes (4 bytes)
└── Data Item(s)Data Types
| Format Code | Type | Description |
|---|---|---|
| 00 | L | List |
| 10 | B | Binary |
| 11 | BOOLEAN | Boolean |
| 20 | A | ASCII |
| 21 | J | JIS-8 |
| 30 | I8 | 8-byte integer |
| 31 | I1 | 1-byte integer |
| 32 | I2 | 2-byte integer |
| 34 | I4 | 4-byte integer |
| 40 | F8 | 8-byte float |
| 44 | F4 | 4-byte float |
| 50 | U8 | 8-byte unsigned |
| 51 | U1 | 1-byte unsigned |
| 52 | U2 | 2-byte unsigned |
| 54 | U4 | 4-byte unsigned |
Common Messages
S1F1 - Are You There
S1F1 W
.S1F13 - Establish Communications
S1F13 W
<L [2]
<A "MDLN">
<A "SOFTREV">
>.S2F41 - Host Command Send
S2F41 W
<L [2]
<A "RCMD">
<L [n]
<L [2]
<A "CPNAME">
<A "CPVAL">
>
>
>.