Y202-R Dual-Port Ethernet DTU Technical Manual

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

Y202-R is the standard dual-port Ethernet DTU in the Yanji portfolio. It converts two independent serial channels (each selectable as RS232 or RS485) to 10/100 M Ethernet while providing dual socket contexts per port, Modbus RTU ↔ TCP gateway, registration packets, heartbeats, HTTP/MQTT clients, and browser-based provisioning. The firmware aligns with the MiniLink Y201 series, enabling mixed deployments with consistent AT commands and OTA workflows.

Item	Description
MCU & OS	Dual-core 240 MHz MCU + RTOS, hardware watchdog
Serial Interfaces	2 × RS232/RS485 (software selectable)
Ethernet	10/100Base‑T RJ45, static/DHCP
Services	Transparent sockets, HTTP Client, MQTT Client, Modbus gateway, JSON scheduler
Form Factor	118 × 89 × 30 mm DIN-rail housing

Mechanical drawings, SKU table, and ordering information reside in the Y202-R Specification.

2. System Overview

Architecture: Industrial MCU with RTOS, dual watchdog, configurable reboot-on-silence, and heartbeats to keep both serial buses online.
Serial Access: COM1 and COM2 can operate as RS232 or RS485, each routed to Socket A/B with independent parameters and Modbus gateway toggles.
Firmware Services: Transparent sockets (TCP/UDP), HTTP Client (GET/POST/AUTO), MQTT Client (with Aliyun helper), Modbus RTU ↔ TCP converter, JSON uploader, offline cache, remote AT, and HTTP OTA.
Indicators: POWER, WORK, and DATA LEDs expose supply, link, and traffic status while optional TX/RX LEDs (per port) show serial activity.

3. Hardware Interfaces

Group	Description
Power	6-pin pluggable terminal providing V+, V-, COM1 A/B (or TX/RX), COM2 A/B (or TX/RX). Optional DC barrel jack (Ø5.5/2.1 mm) wired to V+/V-.
Serial	COM1 and COM2 share the terminal; wiring jumpers plus firmware settings define RS232 (TX/RX/GND) or RS485 (A/B/GND).
Ethernet	Single RJ45 10/100Base‑T, auto MDI/MDIX, LINK (green) / ACT (yellow) indicators.
USB	Micro-USB (CDC) for local console, AT commands, and firmware flashing.
Button	Reload – press 3–10 s to reload saved parameters, >10 s for factory reset.

LED Behavior

LED	Behavior	Meaning
POWER	Steady on	DC supply OK
WORK	Fast blink (~400 ms)	Booting / waiting for 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

4. Electrical Specifications

Parameter	Value
Supply Voltage	9–36 V DC (terminal) + optional 12 V barrel
Typical Current	140 mA @ 12 V with dual sockets active
Operating Temp	-35 °C ~ +75 °C (extended SKU -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 clip or M3 ears

Maintain ≥15 mm clearance for airflow and use shielded twisted pair for RS485 runs with 120 Ω terminations.

5. Serial Configuration & Packaging

5.1 UART Parameters

Per-port command: AT+UARTn=<baud>,<databits>,<stopbits>,<parity>,<fc> (n = 1/2).

Field	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 (AT+UARTTLn)

Length trigger: 64–1024 bytes (default 1024).
Gap trigger: 1–300 ms (default 5 ms).
Either condition flushes the buffer toward sockets.

5.3 Modes

Transparent Mode – Default data tunnel.
AT Command Mode – Enter +++ + guard time + a, exit with AT+EXIT or reboot; sockets pause up to 3 s.

6. Ethernet Networking & Web Console

6.1 Default Profile

Parameter	Value
IP Mode	Static
IP Address	`192.168.10.8`
Gateway	`192.168.10.1`
Netmask	`255.255.255.0`
HTTP Login	`admin` / `admin`

Set your PC to the same subnet, browse to http://192.168.10.8, and configure IP, serial, sockets, Modbus gateway, and heartbeats via the Status/System/Port tabs.

6.2 LAN Commands

DHCP: AT+WAN=DHCP
Static: AT+WAN=STATIC,<ip>,<gw>,<mask>
DNS backup: AT+DNS=<addr> (default 114.114.114.114)
Broadcast discovery: AT+SEARCH=<port>,<keyword> (default 8168/HuayunIOT)

Reboot (AT+REBOOT or web UI) after modifying LAN settings.

7. Socket Protocol Workflows

Each COM port offers Socket A and Socket B. Enable with AT+SOCKENns=ON (n=1/2, s=A/B) and configure via AT+SOCKns=<type>,<addr>,<port>[,localport].

7.1 TCP Server

Default port 8010; accepts up to eight clients per socket. Example:
```
AT+SOCKEN1A=ON
AT+SOCK1A=TCPS,0.0.0.0,8010
AT+REBOOT
```

7.2 TCP Client

Auto-reconnect every second; ideal for upstream SCADA. Example:
```
AT+SOCKEN2B=ON
AT+SOCK2B=TCPC,10.10.10.50,9000
AT+REBOOT
```

7.3 UDP Server/Client

UDPS listens on a local port and responds to the most recent sender.
UDPC targets a fixed IP/port; specify localport to satisfy firewalls.

7.4 HTTP Client

Switch socket to HTPC, set headers via AT+HTPHDn, select GET/POST/AUTO using AT+HTPREQn, and optionally define URL (AT+HTPURLn). AUTO mode lets you send complete URI + payload separated by \r\n.

7.5 MQTT Client

Configure connection (AT+MQCONFn), authentication (AT+MQAUTHn), publish/subscribe topics, and optional Aliyun shortcut. Supports QoS 0/1/2 and keepalive up to 65,535 s.

7.6 Registration Packets & Heartbeats

Registration: 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.

8. Modbus Gateway & JSON Services

Toggle gateway per port using Port tab or AT+MBMDn=ON. Ethernet Modbus TCP frames convert to RTU and return responses automatically.
Scheduler + JSON uploader:
- AT+MBCFGn=<enable>,<interval_ms>,<period_s>
- AT+MBCMDn=<hex frames>
- AT+MBJSn=<mode>,<interval_s>
- AT+HJREG for register metadata, plus AT+JSIMEIn, AT+JSTMn, etc.

Example JSON:

json

{
  "mac": "00-11-22-33-44-55",
  "time": 1733367000,
  "data": {
    "loop_voltage": 228.7,
    "loop_current": 11.9
  }
}

9. Advanced Functions

Feature	Command	Description
Offline Cache	`AT+CACHEn=ON/OFF`	Stores up to 50 frames when the network is down.
Data Conversion	`AT+DTCVTn=<uplink>,<downlink>`	HEX↔RAW conversions.
Enhanced AT	`AT+EXAT=<mode>,<keyword>`	Enables AT parsing over sockets.
No-Data Reboot	`AT+SOCKRTO=<minutes>`	Reboots if no payload within the window (default 1440 min).
HTTP OTA	`AT+DOWNLOAD=<uri>`	Pulls firmware image via HTTP (host:port/path).
Backup/Restore	`AT+BKCFG`, `AT+RSTCFG`, `AT+CLRCFG`	Snapshot, reload, or factory reset.

10. Remote Management & Diagnostics

Enable registration packets (FIRST mode) so servers receive MAC/custom ID whenever sockets connect.
Configure NET heartbeat (e.g., 60 s) to detect link issues; optionally enable UART heartbeat for PLC keepalive.
Set AT+SOCKRTO=30 (minutes) to auto-reboot after prolonged uplink silence.
Keep HTTP OTA endpoint accessible; schedule remote firmware pushes during maintenance windows.
Use AT+BKCFG after commissioning, allowing instant recovery with AT+RSTCFG or Reload button.

Diagnostic commands:

AT+DEVINFO – Model, firmware, MAC, SN.
AT+SOCKLK – Socket status for TCP Clients.
AT+PING=<host> – Network reachability test.
AT+BOOTINFO=<text> – Custom boot banner (1–16 chars).

11. AT Command Highlights

Command	Purpose
`AT+LIST`	Enumerate supported commands
`AT+VER`	Firmware version
`AT+WAN`	Static/DHCP selection
`AT+SOCKns` / `AT+SOCKENns`	Define/enable sockets
`AT+REGTPn`, `AT+REGMDn`, `AT+REGDATn`	Registration packets
`AT+HEARTMDn`, `AT+HEARTTMn`	Heartbeat mode & interval
`AT+MBCFGn`, `AT+MBCMDn`, `AT+MBJSn`, `AT+HJREG`	Modbus/JSON scheduler
`AT+MQCONFn`, `AT+MQAUTHn`, `AT+MQPUBn`	MQTT connection/auth/publish
`AT+HTPURLn`, `AT+HTPHDn`, `AT+HTPREQn`	HTTP client settings
`AT+DOWNLOAD`	HTTP OTA
`AT+SOCKRTO`	Reboot-on-silence timer
`AT+BKCFG`, `AT+RSTCFG`, `AT+CLRCFG`	Backup/restore/factory reset

Linked Documents: Y202-R Specification · DTU Overview
Manufacturer: Hunan Yanji Tech Co.,Ltd · Email: hi@yanjiiot.com

1 Port

2 Ports

4 Ports

8 Ports

Relay Output I/O Modules

Standard I/O Modules

Y202-R Dual-Port Ethernet DTU Technical Manual

Table of Contents

1. Introduction

2. System Overview

3. Hardware Interfaces

LED Behavior

4. Electrical Specifications

5. Serial Configuration & Packaging

5.1 UART Parameters

5.2 Packaging (AT+UARTTLn)

5.3 Modes

6. Ethernet Networking & Web Console

6.1 Default Profile

6.2 LAN Commands

7. Socket Protocol Workflows

7.1 TCP Server

7.2 TCP Client

7.3 UDP Server/Client

7.4 HTTP Client

7.5 MQTT Client

7.6 Registration Packets & Heartbeats

8. Modbus Gateway & JSON Services

9. Advanced Functions

10. Remote Management & Diagnostics

11. AT Command Highlights

Y202-R Dual-Port Ethernet DTU Technical Manual ​

Table of Contents ​

1. Introduction ​

2. System Overview ​

3. Hardware Interfaces ​

LED Behavior ​

4. Electrical Specifications ​

5. Serial Configuration & Packaging ​

5.1 UART Parameters ​

5.2 Packaging (AT+UARTTLn) ​

5.3 Modes ​

6. Ethernet Networking & Web Console ​

6.1 Default Profile ​

6.2 LAN Commands ​

7. Socket Protocol Workflows ​

7.1 TCP Server ​

7.2 TCP Client ​

7.3 UDP Server/Client ​

7.4 HTTP Client ​

7.5 MQTT Client ​

7.6 Registration Packets & Heartbeats ​

8. Modbus Gateway & JSON Services ​

9. Advanced Functions ​

10. Remote Management & Diagnostics ​

11. AT Command Highlights ​

Y202-R Dual-Port Ethernet DTU Technical Manual

Table of Contents

1. Introduction

2. System Overview

3. Hardware Interfaces

LED Behavior

4. Electrical Specifications

5. Serial Configuration & Packaging

5.1 UART Parameters

5.2 Packaging (AT+UARTTLn)

5.3 Modes

6. Ethernet Networking & Web Console

6.1 Default Profile

6.2 LAN Commands

7. Socket Protocol Workflows

7.1 TCP Server

7.2 TCP Client

7.3 UDP Server/Client

7.4 HTTP Client

7.5 MQTT Client

7.6 Registration Packets & Heartbeats

8. Modbus Gateway & JSON Services

9. Advanced Functions

10. Remote Management & Diagnostics

11. AT Command Highlights