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Y201-W Mini WiFi DTU Specification

Reference Manual: Y201-W Technical Manual
Document Control
| Item | Detail |
|---|---|
| Version | V1.0.0 |
| Release Date | December 2025 |
| Product Category | Mini WiFi DTU |
Table of Contents
- Overview
- Ordering Information
- Key Features
- Technical Specifications
- Interfaces & Indicators
- Mechanical & Installation
- Application Notes
1. Overview
Y201-W extends the Y201 mini DTU platform with WiFi uplink while keeping a single selectable serial interface (RS485 / RS232 / TTL). The 74.6 × 22.6 × 18.1 mm body adds AP/STA/AP+STA modes, dual sockets (A/B), Modbus RTU ↔ TCP gateway, registration and heartbeat packets, and HTTP/MQTT clients. It targets retrofits where wired Ethernet is unavailable but WLAN access is present or can be provided via the built-in AP.
| Item | Description |
|---|---|
| MCU & Firmware | 240 MHz dual-core MCU, RTOS, dual watchdog |
| Serial Interface | Single port selectable as RS485 / RS232 / 3.3 V TTL |
| Wireless | 802.11 b/g/n @ 2.4 GHz, AP/STA/AP+STA |
| Power | 5–36 V DC (2-pin terminal) |
| Dimensions | 74.6 × 22.6 × 18.1 mm mini enclosure |
Positioning Highlights
- Palm-sized WiFi DTU that bridges legacy RS485/RS232/TTL devices to WLAN without changing cabinet wiring.
- Dual socket architecture mirrors Y202-W/Y201-R behavior; one serial channel, two logical sockets, multiple protocols.
- Built-in AP for zero-tool commissioning, STA/AP+STA for field integration, and Modbus gateway for RTU/TCP conversion.
- Web console (192.168.4.1) plus AT command set ensures configuration consistency across the MiniLink family.
2. Ordering Information
2.1 Model Naming
Y201-W-IF
- W – WiFi uplink.
- IF – Serial interface option: 485 / 232 / TTL.
2.2 SKU Table
| SKU | Serial Interface | Notes |
|---|---|---|
| Y201-W-485 | RS485 2-wire | Fieldbus retrofit default |
| Y201-W-232 | RS232 3-wire | PLC/HMI and instrument gateways |
| Y201-W-TTL | 3.3 V TTL | Embedded controller integration |
2.3 Standard Package
1 × Y201-W Mini WiFi DTU
1 × 5-pin power/serial plug
1 × WiFi SMA antenna
DIN clip, quick-start card, warranty
Optional: 12 V PSU, USB console lead.
3. Key Features
- WiFi Flexibility – AP, STA, AP+STA modes with WPA/WPA2/WPA3 security; RJ45-free retrofits for mobile or remote cabinets.
- Single Serial, Dual Socket – One RS485/RS232/TTL port routed to Socket A/B supporting TCP/UDP/HTTP/MQTT concurrently.
- Modbus Gateway & JSON Hooks – Built-in RTU ↔ TCP conversion, JSON uploader with Modbus polling, registration packets, and NET/UART heartbeats.
- Industrial Power & Watchdogs – 5–36 V DC input, reverse polarity protection, dual watchdog, Reload button for recovery.
- Mini Form Factor – Same palm-sized housing as Y201-R, enabling clamp-on installations beside PLCs or meters.
- Web + AT Management – Browser console (default 192.168.4.1, admin/admin), LAN discovery, remote AT, HTTP OTA, and parameter backup.
4. Technical Specifications
4.1 Electrical & Environmental
| Parameter | Specification |
|---|---|
| Supply Voltage | 5–36 V DC |
| Typical Current | 60 mA @ 12 V (WiFi idle) |
| Operating Temp | -35 °C ~ +75 °C (extended -40 °C ~ +85 °C) |
| Humidity | 5% ~ 95% RH, non-condensing |
| Protection | Reverse polarity, surge clamp, watchdog reset |
4.2 Serial Interface
| Parameter | Specification |
|---|---|
| Modes | RS485 / RS232 / TTL (order-time selection) |
| Baud Rate | 1,200–460,800 bps (default 115,200) |
| Data Bits | 7 or 8 |
| Stop Bits | 1 or 2 |
| Parity | NONE / EVEN / ODD |
| Packaging | Length 64–1024 bytes, gap 0–300 ms |
4.3 WiFi & Firmware
| Item | Specification |
|---|---|
| WiFi Standard | IEEE 802.11 b/g/n @ 2.4 GHz |
| Modes | AP (default), STA, AP+STA |
| AP Default | SSID W100, IP 192.168.4.1, DHCP enabled |
| Security | WPA/WPA2/WPA3-PSK |
| Sockets | A: TCP/UDP/HTTP/MQTT, B: TCP/UDP |
| Protocols | TCP/UDP/HTTP/MQTT/EDP, Modbus RTU ↔ TCP |
| OTA | HTTP download, web/USB upgrade |
5. Interfaces & Indicators
| Group | Description |
|---|---|
| Power | 5-pin pluggable terminal (V+, V-) |
| Serial | Shared pins for RS485/RS232/TTL per SKU |
| WiFi | SMA antenna connector |
| USB | Micro-USB console/upgrades |
| Button | Reload – hold ≥5 s to factory reset |
| LEDs | POWER (steady), WORK (slow blink = WiFi linked, fast = searching), TX/RX (serial activity) |
Connect the included antenna before powering on to ensure RF performance.
6. Mechanical & Installation

| Item | Value |
|---|---|
| Dimensions | 74.6 × 22.6 × 18.1 mm |
| Weight | ≈35 g |
| Enclosure | PC/ABS, UL94 V-0 |
| Mounting | DIN clip or dual-ear panel mount |
Installation guidelines:
- Provide ≥10 mm clearance for antenna swivel and cable bend radius.
- Route RS485 twisted pairs away from RF antenna to minimize coupling.
- Fuse the DC feed near the source (0.5–1 A slow blow).
7. Application Notes
- Wireless Retrofits – Deploy Y201-W in cabinets lacking Ethernet drops; AP mode offers maintenance access, STA links to plant WiFi.
- Meter & Sensor Gateways – Use RS485 SKU to bridge Modbus loops into MQTT/HTTP cloud services without pulling cable.
- Portable Test Rigs – TTL SKU connects directly to embedded controllers; AP mode plus HTTP client pushes logs to QA dashboards.
- JSON Telemetry – Combine Modbus polling with JSON uploader to send aggregated data to HTTP endpoints; enable cache for spotty WiFi.
- 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
