Y201-R Mini Ethernet DTU Technical Manual

Table of Contents

1. Introduction
2. System Overview
3. Hardware Interfaces
4. Electrical Specifications
5. Serial Configuration & Data Packaging
6. Ethernet Networking & Web Console
7. Socket Protocol Workflows
8. Modbus Gateway & JSON Services
9. Advanced Functions
10. Remote Management & Diagnostics
11. AT Command Highlights

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1. Introduction

Y201-R is the Ethernet member of the MiniLink Y201 DTU family, purpose-built to connect legacy RS485/RS232/TTL assets to modern IP networks without altering cabinet wiring. The unit embeds a dual-core 240 MHz MCU, 10/100M RJ45 uplink, two independent socket contexts (A/B), and a browser-based configuration console. Typical deployments include power automation, building HVAC, environmental monitoring, and OEM controllers where RJ45 is preferred over cellular.

Item	Description
MCU & OS	Dual-core 240 MHz MCU with RTOS scheduler + hardware watchdog
Serial Options	RS485 2-wire, RS232 3-wire, TTL 3.3 V (selectable)
Ethernet	10/100Base-T auto MDI/MDIX, static/DHCP modes
Sockets	Two logical sockets per serial channel (A/B)
Form Factor	74.6 × 22.6 × 18.1 mm, DIN clip or panel ears

Positioning Highlights

• Palm-sized serial server delivering Ethernet uplink, Modbus RTU ↔ TCP conversion, and dual-socket concurrency.
• Built-in length/interval packaging, registration packets, and heartbeats to keep SCADA and cloud peers aware.
• Default web console (192.168.10.8, admin/admin) enables full provisioning without proprietary PC software.

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2. System Overview

• Architecture: Industrial MCU + RTOS with hardware watchdog, exception handler, and configurable reboot policies (no-data timeout, heartbeats).
• Serial Access: Shared UART routes to RS485/RS232/TTL terminals; firmware selects the active interface. UART parameters are configurable via AT commands or the web console.
• Ethernet Stack: Integrated MAC/PHY supporting static IP (default 192.168.10.8/24) or DHCP client. Embedded HTTP server exposes Status/System/Port tabs for commissioning.
• Firmware Services: Dual socket manager (TCP/UDP/HTTP/MQTT/Aliyun), Modbus gateway, registration packets, NET/UART heartbeats, offline cache, data format conversion, remote AT channel, HTTP OTA.
• Indicators: POWER LED (steady), WORK LED (fast blink before IP lease, slow blink after link-up), DATA LED (off=idle, on=connected, blink=traffic), RJ45 LINK/ACT LEDs.

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3. Hardware Interfaces

3.1 Connectors & Buttons

Group	Description
Power	5-pin pluggable terminal (2.54 mm): V+, V-, RS485 A/B or RS232 TX/RX depending on SKU. Reverse-polarity protection built-in.
Serial	RS485 (A/B), RS232 (TX/RX/GND), TTL (TXD/RXD/GND) share the same mechanical footprint—only one is active per configuration.
Ethernet	RJ45 10/100M with LINK (green) and ACT (yellow) indicators, auto MDI/MDIX.
USB	Micro-USB (CDC) for local firmware upgrade and console access.
Button	Reload: press 3–10 s to reload saved parameters, >10 s to factory reset.

3.2 LED Behavior

LED	Behavior	Meaning
POWER	Steady on	Power good
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 on	Socket connected
DATA	Blink	Serial ↔ Ethernet traffic present

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4. Electrical Specifications

Parameter	Value
Supply Voltage	9~36 VDC
Typical Current	110 mA @ 12 V (Ethernet link up)
Power Connector	5-pin pluggable terminal
Operating Temp	-35 °C ~ +75 °C (standard); -40 °C ~ +85 °C (extended SKU)
Storage Temp	-40 °C ~ +85 °C
Humidity	5%~95% RH non-condensing
Protection	Reverse polarity, EFT/ESD IEC 61000-4-2 Level 4
Mounting	DIN rail clip or dual M3 ears

Recommendation: maintain ≥10 mm clearance for airflow and wiring. Use shielded twisted-pair for RS485 runs and bond shield at one end.

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5. Serial Configuration & Data Packaging

5.1 UART Parameters

AT+UARTn=<baud>,<databits>,<stopbits>,<parity>,<flow>

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 / 485	NFC

5.2 Packaging Logic

AT+UARTTLn=<interval_ms>,<length_bytes>

• Length trigger: when accumulated payload reaches 64–1024 bytes (default 1024) it is forwarded to the active socket.
• Gap trigger: when inter-character gap ≥1–300 ms (default 5 ms) the buffer is flushed.
• TCP streams should retain application delimiters because Ethernet introduces segmentation/coalescing.

5.3 Operation Modes

• Transparent Mode: default; serial data is tunneled to sockets.
• AT Command Mode: entered via +++ + guard time + a. Device responds to AT commands; sockets pause up to 3 s. Exit via AT+EXIT or reboot.

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6. Ethernet Networking & Web Console

6.1 Default Network Profile

• Factory IP: 192.168.10.8
• Netmask: 255.255.255.0
• Gateway: 192.168.10.1
• HTTP login: username admin, password admin

Steps:

1. Power the DTU and connect PC via RJ45.
2. Assign the PC an address within 192.168.10.x/24 (e.g., 192.168.10.100/24, gateway 192.168.10.1).
3. Browse to http://192.168.10.8, log in with admin/admin.
4. Update IP to static or switch to DHCP, configure serial parameters, Modbus gateway, socket profiles, and click Save then Reboot.

Virtual COM Helper: When the upper system only accepts COM ports, install the vendor virtual serial driver, ensure port numbers do not conflict, then add a virtual COM and click Start. If the driver fails, disable Secure Boot and run bcdedit /set nointegritychecks on, reboot, and retry. Disable Windows firewall or inspect intranet ACLs if TCP connections cannot be established.

6.2 Web Tabs

• Status: IP information, socket state, uptime, firmware version.
• System: static/DHCP selection, MAC address, admin password, firmware upgrade, reboot controls.
• Port: serial parameters, Modbus gateway toggle, Socket A/B protocol, registration packets (FIRST/EVERY/ALL), NET/UART heartbeats.

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7. Socket Protocol Workflows

7.1 Supported Modes

Socket	Protocols
A	TCP Server, TCP Client, UDP Server, UDP Client, HTTP Client, MQTT Client
B	TCP Client, UDP Server, UDP Client

7.2 TCP Server

• Listens on a user-defined port (default 8010). Accepts up to eight concurrent clients; the oldest session is dropped if the limit is exceeded.
• Serial payload is broadcast to all connected clients; inbound IP frames are multiplexed to the UART.

7.3 TCP Client

• After obtaining IP, the DTU dials the configured server. If the link fails, auto-reconnect occurs every second until success.
• Typical flow: configure server IP/port → save → reboot → monitor WORK/DATA LEDs and server logs.

7.4 UDP Server

• Binds to a local port; accepts datagrams from any origin. Response target is set to the most recent sender.

7.5 UDP Client

• Sends packets to a fixed destination IP/port. For best interoperability, fix the local source port so the peer knows where to reply.

7.6 HTTP Client

Modes include GET, POST, AUTO. Configure via AT+HTPURLn, AT+HTPHDn, AT+HTPREQn or the Port tab. GET mode uses incoming serial data as the URL path. POST mode stores server address/port/URL and forwards serial payload as the HTTP body. AUTO mode allows the user to define method, URL, and payload dynamically (URL and body separated by \r\n).

7.7 MQTT Client

• Standard MQTT 3.1/3.1.1 with QoS 0/1/2. Supports username/password authentication, clean session flag, keepalive 30–65535 s, and optional last-will messages.
• Aliyun shortcut mode maps ProductKey/DeviceName/DeviceSecret automatically, minimizing configuration effort.

QoS	Delivery Guarantee	Notes
0	At most once	Lowest latency, no retry
1	At least once	Retries until acknowledged; duplicates possible
2	Exactly once	Highest reliability, additional handshake

Aliyun credential mapping:

MQTT Field	Aliyun Mapping
Client ID	ProductKey + DeviceName (Aliyun format)
Username	DeviceName
Password	DeviceSecret

7.8 Registration Packets & Heartbeats

• Registration Packet: Appends IMEI/ICCID/user-defined payload to the first connection (FIRST), to every data frame (EVERY), or both (ALL). Useful for server-side device identification.
• Heartbeat: NET heartbeats support TCP/UDP Client; UART heartbeats are independent of network mode. Typical uses: server keepalive (NET) or PLC trigger (UART). Heartbeats pause automatically while the device is in AT command mode.

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8. Modbus Gateway & JSON Services

8.1 Modbus RTU ↔ TCP Gateway

• When enabled, Ethernet-side Modbus TCP frames are converted to RTU and forwarded to the serial bus; serial responses are translated back to TCP.
• Disable the gateway when using pure transparent sockets to avoid unnecessary parsing.

8.2 Modbus Polling & JSON Uplink

• Scheduler: AT+MBCFGn=<enable>,<interval_ms>,<period_s> defines scan interval and upload cadence.
• Commands: AT+MBCMDn=<hex>|<hex2>|... (≤240 bytes total) stores poll frames.
• JSON Mapping: AT+MBJSn=<mode>,<interval_s> selects OFF / POLL / ALL, while AT+HJREG defines register metadata (address, type, scaling, key name).
• Optional JSON fields include timestamp (AT+JSTMn), identifiers (AT+JSIMEIn, AT+JSICCIDn), IO snapshot, and user-defined key-value pairs.
• Error handling via AT+JSERRn: report null or 0 on poll failure.

8.3 Example Payload

{
  "mac": "00-11-22-33-44-55",
  "time": 1685581200,
  "data": {
    "voltage": 229.8,
    "current": 12.4,
    "status": 1
  }
}

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9. Advanced Functions

Feature	Command / Setting	Description
Offline Cache	AT+CACHEn=ON/OFF	Stores up to 50 frames (~20 KB). Flushes when link recovers.
Data Conversion	AT+DTCVTn=<uplink>,<downlink>	Converts RAW↔HEX per direction.
Enhanced AT	AT+EXAT=<mode>,<keyword>	Triggers AT parsing over NET/UART streams using a keyword (default NAT@).
No-Data Reboot	AT+SOCKRTO=<minutes>	Reboots if no network payload within window (default 1440 min).
HTTP OTA	AT+DOWNLOAD=<host:port/file>	Downloads firmware via HTTP and reboots automatically.

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10. Remote Management & Diagnostics

10.1 Monitoring Tools

• AT+DEVINFO reports model, firmware, MAC, serial number.
• AT+SOCKLK reveals socket status (ON/OFF, peer IP/port).
• AT+PING=<host> checks reachability (useful after DHCP changes).

10.2 Maintenance Workflow

1. Enable registration packets (FIRST mode) so the server receives IMEI/MAC at every connection.
2. Configure NET heartbeat (e.g., 60 s) to detect dead links.
3. Enable AT+SOCKRTO (e.g., 30 min) so the DTU reboots if a remote server is unreachable for extended periods.
4. Keep the HTTP OTA endpoint accessible to push firmware updates remotely.

10.3 Backup & Recovery

• AT+BKCFG saves the current configuration snapshot.
• AT+RSTCFG reloads the snapshot.
• AT+CLRCFG restores factory defaults.
• Reload button mirrors AT+RSTCFG; holding >10 s equals AT+CLRCFG.

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11. AT Command Highlights

Below is a condensed list focusing on Ethernet-related commands.

Command	Purpose	Notes
AT+LIST	List supported commands	Returns lines formatted as +LIST:AT+CMD
AT+VER	Firmware version	+VER:V1.0.0
AT+IPMODE=<mode>	Static/DHCP selection	STATIC or DHCP
AT+NETIP=<ip>,<mask>,<gw>	Configure static IP	Requires reboot
AT+SOCKns=<type>,<addr>,<port>	Socket definition	Types TCPS/TCPC/UDPS/UDPC/HTPC/MQTT
AT+SOCKENns=<state>	Enable socket n/s	ON/OFF
AT+REGTPn, AT+REGMDn, AT+REGDATn	Registration packets	Type (IMEI/ICCID/USER), mode (OFF/FIRST/EVERY/ALL), payload
AT+HEARTMDn, AT+HEARTTMn, AT+HEARTDATn	Heartbeats	Modes OFF/NET/UART; interval 1–65535 s
AT+MBCFGn, AT+MBCMDn, AT+MBJSn, AT+HJREG	Modbus scheduler & JSON	Aligns with Section 8
AT+MQCONFn, AT+MQAUTHn, AT+MQPUBn, AT+MQSUBn, AT+MQMDn	MQTT connect/auth/publish	Supports Aliyun shortcut
AT+HTPURLn, AT+HTPHDn, AT+HTPREQn, AT+HTPTOn	HTTP client settings	GET/POST/AUTO
AT+DOWNLOAD=<uri>	HTTP OTA	host:port/path
AT+SOCKRTO=<minutes>	Reboot-on-silence	0 disables
AT+RSTCFG, AT+BKCFG, AT+CLRCFG	Restore/save/factory reset	Matches button behavior

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• Manufacturer: Hunan Yanji Tech Co.,Ltd
• Address: Room 21014, Unit 1, Fudixingguang plaza, Yuhua district Yingxin road, Changsha, Hunan, P.R. China
• Email: hi@yanjiiot.com
• Website: www.yanjiiot.com