OTA (Over-The-Air) Packet
| Field | Size (bits) | Bit Range | Description | Breakdown |
|---|---|---|---|---|
| Header (10 Bytes) | ||||
| Start byte | 8 | 0–7 | Starting character $ (ASCII value 36) | $ |
| Data length | 12 | 8–18 | 2-byte length of the data following the header | — |
| Num of data packets | 5 | 19–23 | Number of packets (0–32) | 0 - 32 |
| IMEI | 50 | 24–74 | Unique device identifier | Integer type: e.g., 887744556677882 |
| Packet Type | 5 | 75–79 | Type of packet |
00 - Device info |
| Data (154 Bytes) | ||||
| OTA Source | 5 | 80-84 | Source of OTA |
00 - OTA_SRC_SERIAL |
| Error status | 8 | 85-92 | Non-zero value indicates an error | 0 = No Error, Non-zero = Error |
| Cell Number | 51 | 93-143 | First bit (MSB) indicates presence of country code. Remaining 50 bits = mobile number |
Example: 400D6276ACF52 (+919784312658) |
| Date & Time | 32 | 144-175 | UTC Timestamp | UTC time in seconds |
| Timezone | 8 | 176-183 | Timezone in quarter-hours (e.g., 22 = +5:30) |
22 × 15 mins = 330 mins = +5:30 |
| Command Length | 8 | 184-191 | Length of command string | — |
| Command | up to 600 bits (75 bytes) | 192-791 | Command with arguments, null-terminated string |
Example: SET CUIOCFG:IO1-DI-IGN*IO2_AN_GEN*IO3-DI-PBN*IO4-DO-IMB* |
| Response Length | 8 | 792-799 | Length of response string | — |
| Response | up to 512 bits (64 bytes) | 800-1311 | Response string from device |
Example: IOCFG:IO1-DI-IGN*IO2-AN_GEN*IO3-DI-PBN*IO4-DO-IMB* |
| Tail (2 Bytes) | ||||
| End Character | 8 | 0–7 | End character * (ASCII value 42) | * |
| CRC | 8 | 8–15 | 8-bit XOR CRC from $ to * (excluding both) | — |
Sample Packet
{"HEX:240340e1cabd09208ca210000000000000006824646f160947455420545355524c1c55524c3a5443503a3134312e3134372e3132382e3135303a383738382aa2",
"cell_no": 0,
"command": "GET TSURL",
"command_length": 9,
"dateTime": 1747215471,
"dateTime_tz": "2025-05-14 15:07:51.000",
"error_status": 0,
"imei": 860187062240357,
"insert_time": "Wed, 14 May 2025 09:38:03 GMT",
"ota_source": 2,
"packetType": 2,
"response": "URL:TCP:141.147.128.150:8788",
"response_length": 28,
"send_time": "2025-05-14 15:07:51",
"timezone": 22}
OTA Packet Parser
Parsed Output:
| Field | Value |
|---|