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Y208-R Octo-Port Ethernet DTU Technical Manual
Table of Contents
- Introduction
- System Overview
- Hardware Interfaces
- Electrical Specifications
- Serial Configuration & Packaging
- Ethernet Networking & Web Console
- Socket Protocol Workflows
- Modbus Gateway & JSON Services
- Advanced Functions
- Remote Management & Diagnostics
- AT Command Highlights
1. Introduction
Y208-R is the highest-density member of Yanji’s Ethernet DTU lineup. It connects up to eight serial channels (RS232/RS485 selectable per port) to dual 10/100 M Ethernet uplinks while preserving the firmware experience introduced with Y201/Y202/Y204 models. Each COM port exposes Socket A/B contexts, programmable registration packets, Modbus RTU ↔ TCP conversion, heartbeats, and browser-based controls for SCADA, MES, power automation, and environmental telemetry deployments.
| Item | Description |
|---|---|
| MCU & OS | Dual-core 240 MHz MCU + RTOS scheduler with hardware watchdog |
| Serial Interfaces | 8 × RS232/RS485 selectable, galvanically isolated |
| Ethernet | Dual RJ45 (LAN1/LAN2) with independent IP stacks |
| Services | Transparent sockets, HTTP Client, MQTT Client, Modbus gateway, JSON uploader |
| Form Factor | 190 × 115 × 40 mm DIN-rail metal enclosure |
Positioning Highlights
- 16 concurrent sockets (8 ports × 2 sockets) for simultaneous SCADA, cloud, and maintenance channels.
- LAN1/LAN2 separation enables redundant control rooms or segmented enterprise/OT networks.
- Browser console (default
192.168.10.8) and AT command set accelerate commissioning. - Firmware parity with Y20x family ensures consistent AT commands, heartbeat behavior, and OTA process.
For mechanical data, wiring diagrams, and ordering options see the Y208-R Specification.
2. System Overview
- Architecture: High-performance MCU + RTOS with hardware watchdog, configurable reboot-on-silence, NET/UART heartbeats, and exception handlers to keep all eight buses online.
- Serial Access: COM1–COM8 share identical capabilities; each can be wired as RS232 (TX/RX/GND) or RS485 (A/B/GND) and mapped to Socket A/B with independent parameters.
- Ethernet Stack: Two RJ45 ports (LAN1/LAN2) each support static IP or DHCP client mode, independent MAC addresses, and built-in HTTP configuration server.
- Firmware Services: Dual sockets per port with TCP/UDP/HTTP/MQTT, Modbus RTU ↔ TCP gateway, JSON uploader, registration packets, NET/UART heartbeats, offline cache, remote AT channel, and HTTP OTA.
- Indicators: POWER, WORK, DATA LEDs reflect system state; optional per-port TX/RX LEDs show serial traffic.
3. Hardware Interfaces
3.1 Connectors & Buttons
| Group | Description |
|---|---|
| Power | 2-wire terminal (V+/V-) plus two DC barrel jacks (Ø5.5/2.1 mm) for redundant supplies tied internally to V+/V-. |
| Serial | Four detachable terminal blocks labelled COM1–COM8 (two ports per block). Each port presents TX/RX/GND when in RS232 mode or A/B/GND in RS485 mode. Selection is via firmware settings and wiring jumpers. |
| Ethernet | LAN1 and LAN2 RJ45, 10/100Base‑T auto MDI/MDIX, LINK (green) and ACT (yellow) indicators per port. |
| USB | Micro-USB (CDC) for local console, AT commands, and firmware flashing. |
| Button | Reload: press 3–10 s to reload saved parameters; >10 s triggers factory reset (equivalent to AT+CLRCFG). |
3.2 LED Behavior
| LED | Behavior | Meaning |
|---|---|---|
| POWER | Steady on | DC input healthy |
| WORK | Fast blink (~400 ms) | Booting / awaiting IP |
| WORK | Slow blink (~2 s) | IP acquired, sockets ready |
| DATA | Off | No socket session |
| DATA | Steady | Socket connected |
| DATA | Blink | Serial ↔ Ethernet traffic present |
| TX/RX (optional) | Blink per port | Serial transmission/reception on corresponding COM |
4. Electrical Specifications
| Parameter | Value |
|---|---|
| Supply Voltage | 9–36 V DC terminal + dual 12 V barrel inputs |
| Typical Current | 360 mA @ 12 V (all ports active) |
| Operating Temp | -35 °C ~ +75 °C (extended SKU -40 °C ~ +85 °C) |
| Storage Temp | -40 °C ~ +85 °C |
| Humidity | 5%–95% RH, non-condensing |
| Protection | Reverse polarity, EFT/ESD IEC 61000-4-2 Level 4 |
| Mounting | 35 mm DIN rail or panel ears |
Maintain ≥25 mm clearance for airflow and use shielded twisted pair for RS485 buses with 120 Ω termination at both ends.
5. Serial Configuration & Packaging
5.1 UART Parameters
Per-port AT command: AT+UARTn=<baud>,<databits>,<stopbits>,<parity>,<fc> where n = 1…8.
| Field | Range/Options | Default |
|---|---|---|
| Baud Rate | 1,200–460,800 bps | 115,200 |
| Data Bits | 7 / 8 | 8 |
| Stop Bits | 1 / 2 | 1 |
| Parity | NONE / EVEN / ODD | NONE |
| Flow Control | NFC (RS232) / 485 (auto-direction) | NFC |
5.2 Packaging Logic
AT+UARTTLn=<interval_ms>,<length_bytes> controls length/gap triggers.
- Length trigger: buffer flushes when ≥64–1024 bytes (default 1024).
- Gap trigger: buffer flushes when inter-character gap ≥1–300 ms (default 5 ms).
TCP links may coalesce frames; ensure application-level delimiters if payload boundaries are critical.
5.3 Modes
- Transparent Mode (default): serial data is forwarded to active sockets.
- AT Command Mode: enter via
+++guard time +a, exit withAT+EXITor reboot; sockets pause up to 3 s.
6. Ethernet Networking & Web Console
6.1 Default Profiles
| Port | IP Mode | Default Address |
|---|---|---|
| LAN1 | Static | 192.168.10.8/24, gateway 192.168.10.1 |
| LAN2 | Disabled by default (enable via AT/web) |
Login from a PC configured on the same subnet: browse to http://192.168.10.8, username admin, password admin.
6.2 Web Tabs
- Status – Displays LAN1/LAN2 IP, socket status, uptime, firmware version.
- System – Static/DHCP selection per LAN, MAC view, admin password, firmware upgrade, reboot controls.
- Ports – Serial parameters per COM, RS232/RS485 selection, socket definitions, Modbus gateway toggle, registration packets, heartbeats, JSON scheduler.
6.3 LAN Configuration Commands
- DHCP:
AT+WAN1=DHCP/AT+WAN2=DHCP. - Static:
AT+WAN1=STATIC,<ip>,<gw>,<mask>. - DNS backup:
AT+DNS=<addr>(default114.114.114.114). - Search settings for broadcast discovery:
AT+SEARCH=<port>,<keyword>(default port 8168, keywordHuayunIOT).
After modifying LAN parameters, issue
AT+REBOOTor reboot via web UI.
7. Socket Protocol Workflows
Each COM port offers Socket A and Socket B. Enable with AT+SOCKENns=ON (n = port, s = A/B) and configure via AT+SOCKns=<type>,<addr>,<port>[,localport].
7.1 TCP Server
- Listens on a configured port (default 8010). Up to eight concurrent clients per socket; oldest connection is dropped when the limit is exceeded. Use
AT+SOCK1A=TCPS,0.0.0.0,8010.
7.2 TCP Client
- Auto-dials the target after IP acquisition; reconnect interval 1 s. Example:
AT+SOCKEN3B=ON AT+SOCK3B=TCPC,192.168.10.50,9000 AT+REBOOT
7.3 UDP Server/Client
UDPSbinds a local port and replies to the latest sender.UDPCtargets a fixed remote IP/port; consider fixing local port for firewall rules.
7.4 HTTP Client
- Set mode via
AT+SOCKns=HTPC,<host>,<port>. - Configure headers (
AT+HTPHDn), method (AT+HTPREQn=GET/POST/AUTO), and optional URL (AT+HTPURLn). - AUTO mode allows embedding URL + payload separated by
\r\n.
7.5 MQTT Client
- Supports QoS 0/1/2, username/password, clean session, keepalive (30–65,535 s).
- Aliyun helper maps ProductKey/DeviceName/DeviceSecret automatically. Use
AT+MQCONFn,AT+MQAUTHn,AT+MQPUBn,AT+MQSUBn.
7.6 Registration Packets & Heartbeats
- Registration packets:
AT+REGTPn(MAC/CUS),AT+REGMDn(OFF/FIRST/EVERY/ALL),AT+REGDATn(custom payload). - Heartbeats:
AT+HEARTMDn(OFF/NET/UART),AT+HEARTTMn=<seconds>,AT+HEARTDATn=<payload>.
8. Modbus Gateway & JSON Services
8.1 RTU ↔ TCP Conversion
- Toggle per port using the Port tab or
AT+MBMDn=ON/OFF. When enabled, Ethernet Modbus TCP frames are translated to RTU over the selected COM port; responses are forwarded back to the socket. Disable gateway mode when performing pure transparent transmission to avoid unintended parsing.
8.2 Modbus Polling & JSON Upload
| Command | Purpose |
|---|---|
AT+MBCFGn=<enable>,<interval_ms>,<period_s> | Scheduler enable, scan interval, reporting period |
AT+MBCMDn=<hex frames> | Stores poll commands (≤240 bytes) |
AT+MBJSn=<mode>,<interval_s> | JSON uploader OFF / POLL / ALL |
AT+HJREG=<addr>,<type>,<scale>,<key> | Defines register metadata for JSON payload |
AT+JSIMEIn, AT+JSICCIDn, AT+JSTMn | Adds identifiers and timestamps |
Example JSON payload:
json
{
"mac": "00-11-22-33-44-55",
"time": 1733370000,
"data": {
"feeder1_voltage": 229.8,
"feeder1_current": 12.4,
"breaker_status": 1
}
}9. Advanced Functions
| Feature | Command / Setting | Description |
|---|---|---|
| Offline Cache | AT+CACHEn=ON/OFF | Stores up to 50 frames (~20 KB) per port when network is unavailable. |
| Data Conversion | AT+DTCVTn=<uplink>,<downlink> | RAW↔HEX conversion per direction. |
| Enhanced AT | AT+EXAT=<mode>,<keyword> | Enables AT parsing over NET/UART using a trigger keyword (default NAT@). |
| No-Data Reboot | AT+SOCKRTO=<minutes> | Reboots after minutes without network payload (default 1440). |
| HTTP OTA | AT+DOWNLOAD=<host:port/path> | Downloads firmware and stores to flash; reboot to apply. |
| Backup/Restore | AT+BKCFG, AT+RSTCFG, AT+CLRCFG | Save snapshot, reload, or restore factory defaults. |
10. Remote Management & Diagnostics
10.1 Monitoring Tools
AT+DEVINFO– Model, firmware version, MAC, SN, production date.AT+SOCKLK– Socket status (ON/OFF) for each TCP Client.AT+PING=<host>– ICMP reachability test.AT+BOOTINFO=<string>– Sets boot banner (1–16 bytes) for deployment identification.
10.2 Maintenance Workflow
- Enable registration packets in FIRST mode to deliver MAC or custom ID on every connection.
- Configure NET heartbeat (e.g., 60 s) and UART heartbeat (if PLC expects keepalive).
- Set
AT+SOCKRTO=30(minutes) so the DTU reboots if upstream servers remain unreachable. - Keep HTTP OTA server accessible; schedule maintenance windows for remote firmware pushes.
- Use
AT+BKCFGafter commissioning to snapshot “golden” settings, allowing quick restores withAT+RSTCFG.
10.3 Backup & Recovery
- Reload button =
AT+RSTCFG(restore snapshot). - Hold Reload >10 s =
AT+CLRCFG(factory defaults). - Maintain documented parameter sets (JSON export from Port tab) for audits.
11. AT Command Highlights
| Command | Purpose | Notes |
|---|---|---|
AT+LIST | List supported commands | Returns +LIST:AT+CMD lines |
AT+VER | Firmware version | +VER:V1.0.0 |
AT+WAN1/2 | Configure LAN1/LAN2 IP mode | DHCP or STATIC,<ip>,<gw>,<mask> |
AT+SOCKns | Define socket protocol | TCPS/TCPC/UDPS/UDPC/HTPC/MQTT |
AT+SOCKENns | Enable socket | ON/OFF per port and socket |
AT+REGTPn, AT+REGMDn, AT+REGDATn | Registration packet type/mode/payload | Supports MAC or custom |
AT+HEARTMDn, AT+HEARTTMn, AT+HEARTDATn | Heartbeat mode/interval/payload | NET or UART |
AT+MBCFGn, AT+MBCMDn, AT+MBJSn, AT+HJREG | Modbus polling & JSON mapping | Aligns with Section 8 |
AT+MQCONFn, AT+MQAUTHn, AT+MQPUBn, AT+MQSUBn | MQTT connect/auth/publish/subscribe | Aliyun shortcut supported |
AT+HTPURLn, AT+HTPHDn, AT+HTPREQn, AT+HTPTOn | HTTP client URL/header/method/timeout | AUTO mode simplifies dynamic requests |
AT+DOWNLOAD=<uri> | HTTP OTA firmware fetch | host:port/path |
AT+SOCKRTO=<minutes> | Reboot-on-silence timer | 0 disables |
AT+BKCFG, AT+RSTCFG, AT+CLRCFG | Backup/restore/factory reset | Mirror Reload button behavior |
- Linked Documents: Y208-R Specification · DTU Overview
- Manufacturer: Hunan Yanji Tech Co.,Ltd · Email: hi@yanjiiot.com