# PW41-AC RS485 Wi-Fi Bluetooth Serial Device Server (AC Power)

> AC-powered RS485 Wi-Fi/BLE serial device server for industrial serial equipment, with 2.4 GHz Wi-Fi and BLE 5.0 data exchange.

- **URL**: https://www.iiotsys.net/products/pw41-ac-rs485-wi-fi-bluetooth-serial-device-server-ac-power
- **Markdown**: https://www.iiotsys.net/products/pw41-ac-rs485-wi-fi-bluetooth-serial-device-server-ac-power.md
- **Model**: PW41-AC
- **SKU**: IIS-SG-PW41-AC
- **Price**: $28.00 USD
- **Category**: Industrial Gateways & Serial Servers

## Overview

The IIoTSys PW41-AC connects one RS485 serial interface to a 2.4 GHz Wi-Fi network and supports BLE 5.0. It is intended for serial equipment in industrial automation, power and energy, rail transit, public facilities, and building control. This AC-powered variant accepts 100–240 VAC, 50–60 Hz. The processor runs at 160 MHz with 8 MB Flash, 352 KB SDRAM, and the mbed operating system.

The Wi-Fi interface supports IEEE 802.11 b/g/n over 2.412–2.472 GHz and uses an SMA external antenna connection. STA mode connects the device to a wireless router. AP mode lets a host connect directly to the device. Simultaneous AP+STA mode supports both interfaces, with separate IP subnets for AP and STA. In AP+STA mode, the STA interface needs a router connection. Repeated router scans can otherwise disrupt AP traffic and cause data loss.

BLE provides two functions: app-based BLE provisioning and bidirectional Bluetooth–serial data transmission. BLE is therefore available for serial data exchange as well as network setup. App-based Wi-Fi provisioning is also supported. These functions provide alternatives to configuration through the web interface or companion configuration software.

For network integration, the device supports TCP, UDP, MQTT, HTTP, WebSocket, and virtual serial port modes. Bidirectional Modbus TCP and Modbus RTU conversion supports timed acquisition and data format conversion. Serial framing includes 7 or 8 data bits, 1 or 2 stop bits, and None, Even, or Odd parity. Software Xon/Xoff flow control is available; hardware flow control is not supported. Connect A+ to A+ and B− to B−. A shared GND is recommended under severe interference.

Configuration options include web pages, serial CLI commands, XML file import, Telnet, and companion configuration software. The documented security options include TLS 1.2, AES-128, and DES3. Registration packets and heartbeat packets support connection maintenance. Firmware updates are available through the web interface, companion configuration software, and wireless OTA.

The enclosure measures 102.03 × 64.95 × 27.50 mm and mounts on a C45 guide rail. The specified operating temperature is −40 to +85 °C. Net, Active, Power, and Link indicators show network, serial, supply, and server-channel status. A short press of Reload enters app-based provisioning; holding it for more than 4 seconds and releasing it restores factory settings. Reset performs a hardware reset.

## Description

RS485-to-Wi-Fi/BLE serial device server with 100–240 VAC, 50–60 Hz input. Supports 2.4 GHz Wi-Fi, BLE 5.0 provisioning and serial data exchange, and bidirectional Modbus TCP/RTU conversion.

## Specifications

- Model: PW41-AC
- SKU: IIS-SG-PW41-AC
- Product type: RS485-to-Wi-Fi/BLE serial device server / protocol gateway
- CPU: 160 MHz
- Memory: 8 MB Flash / 352 KB SDRAM (manual terminology)
- OS: mbed
- Serial interface: 1 × RS485
- Serial terminals: Pin 5: B−; pin 6: GND; pin 7: A+
- Serial wiring: Connect A+ to A+ and B− to B−. A shared GND is recommended under severe interference.
- RS485 bus capacity: Up to 32 terminal devices, subject to installation conditions
- RS485 communication distance: Up to 1200 m as listed in the manual; installation dependent
- RS485 termination: 120 Ω; the manual generally recommends termination for wiring over 300 m
- Baud rate: TTL: 1200–230400 bps as labeled in the manual; applicability to the external serial interface requires confirmation
- Data bits: 7 / 8
- Stop bits: 1 / 2
- Parity: None / Even / Odd
- Flow control: Software Xon/Xoff; no hardware flow control
- Wi-Fi standards: IEEE 802.11 b/g/n
- Wi-Fi band: 2.4 GHz
- Wi-Fi frequency range: 2.412–2.472 GHz
- Wi-Fi operating modes: STA / AP / AP+STA
- AP+STA limitations: AP and STA must use different IP subnets. Keep STA connected to a router; repeated scans can disrupt AP traffic and cause data loss.
- Wi-Fi security: WEP / WPA-PSK / WPA2-PSK
- Wi-Fi encryption: WEP64 / WEP128 / TKIP / AES
- Wi-Fi transmit power: 802.11b: +17 ± 1.5 dBm, max. at 11 Mbps; 802.11g: +15 ± 1.5 dBm, max. at 54 Mbps; 802.11n: +14 ± 1.5 dBm, max. at HT20 MCS7
- Wi-Fi receive sensitivity: 802.11b: −89 dBm; 802.11g: −76 dBm; 802.11n: −73 dBm; test rates unspecified
- Antenna interface: Wi-Fi 2.4 GHz SMA external antenna connection
- Bluetooth standard: BLE 5.0
- Bluetooth functions: App-based BLE provisioning and bidirectional Bluetooth–serial data transmission
- BLE transmit power: Maximum 15 dBm, as listed in the manual
- BLE receive sensitivity: −97 dBm, as listed in the manual; test conditions unspecified
- Network protocols: IP, TCP, UDP, DHCP, DNS, ARP, AutoIP, ICMP, NTP, WebSocket, Telnet, HTTP Client, MQTT, Modbus TCP
- Uplink modes: TCP / UDP / MQTT / HTTP / WebSocket / virtual serial port
- Industrial protocol: Bidirectional Modbus TCP and Modbus RTU conversion; timed acquisition; data format conversion
- Transport/data security: TLS 1.2 / AES-128 / DES3
- Connection maintenance: Registration packets and heartbeat packets
- Configuration: Web interface, serial CLI, XML file import, Telnet, companion configuration software, app-based Wi-Fi provisioning, and app-based BLE provisioning
- Web interface: HTTP configuration pages; customizable HTTP pages
- Firmware update: Web interface, companion configuration software, and wireless OTA
- Indicators: Net: Wi-Fi/network status; Active: serial activity; Power: supply status; Link: server communication-channel connection
- Buttons: Reload: short press for app-based Wi-Fi or BLE provisioning; hold >4 s and release to restore factory settings. Reset: hardware reset.
- Input voltage: 100–240 VAC, 50–60 Hz
- Power terminals: Pin 1: L; pin 2: N
- Working current: Peak: 350 mA for 1 ms in 100 ms; average: 40 mA in STA networked standby, 60 mA in STA at 1 KB/s, 70 mA in AP mode. Family-table values; test supply voltage unspecified.
- Power dissipation: Approx. 900 mW, as listed in the family table; test conditions unspecified
- Operating temperature: −40 to +85 °C
- Storage environment: −45 to +105 °C; 5–95% RH, non-condensing
- Dimensions: 102.03 × 64.95 × 27.50 mm
- Mounting: C45 guide rail

## Protocols

- Wi-Fi (native): IEEE 802.11 b/g/n; 2.412–2.472 GHz; STA / AP / AP+STA
- RS-485 (native): Pin 5: B−; pin 6: GND; pin 7: A+
- Bluetooth (native): BLE 5.0; app-based BLE provisioning and bidirectional Bluetooth–serial data transmission
- Modbus RTU/TCP (convert): Bidirectional conversion, timed acquisition, and data format conversion
- MQTT (native): Uplink communication mode
- TCP (native): Serial data uplink
- UDP (native): Serial data uplink
- HTTP (native): HTTP Client uplink and HTTP web configuration
- WebSocket (native): Uplink communication mode
- Virtual serial port (native): Serial connectivity mode
- IP (native): Network stack
- DHCP (native): Network stack
- DNS (native): Network stack
- ARP (native): Network stack
- AutoIP (native): Network stack
- ICMP (native): Network stack
- NTP (native): Network stack
- Telnet (native): Parameter configuration
- TLS 1.2 (native): Security protocol listed in the manual

## Features

- One RS485 interface; 100–240 VAC, 50–60 Hz input
- IEEE 802.11 b/g/n on 2.4 GHz; STA, AP, and AP+STA modes
- BLE 5.0 for app-based provisioning and bidirectional Bluetooth–serial data transmission
- Wi-Fi 2.4 GHz SMA external antenna connection
- 160 MHz processor; 8 MB Flash / 352 KB SDRAM; mbed OS
- TCP, UDP, MQTT, HTTP, WebSocket, and virtual serial port modes
- Bidirectional Modbus TCP/RTU conversion, timed acquisition, and data format conversion
- 7/8 data bits; 1/2 stop bits; None/Even/Odd parity; software Xon/Xoff
- Web, serial CLI, XML import, Telnet, companion software, and app-based Wi-Fi or BLE provisioning
- TLS 1.2, AES-128, and DES3; registration and heartbeat packets
- Web, companion-software, and wireless OTA firmware updates
- −40 to +85 °C operation; 102.03 × 64.95 × 27.50 mm enclosure; C45 guide-rail mounting

## Use cases

- RS485 equipment networking over Wi-Fi in industrial automation
- Power and energy serial-device data connectivity
- Rail transit and public-facility serial communications
- Building automation and control with serial equipment
- Modbus RTU equipment integration with Modbus TCP over Wi-Fi
- Local bidirectional Bluetooth–serial data exchange

## FAQ

### Which serial interface does the PW41-AC provide?
It provides one RS485 interface. Connect A+ to A+ and B− to B−. A shared GND is recommended under severe interference.
### Which power supply does this variant require?
The PW41-AC accepts 100–240 VAC, 50–60 Hz. Power input uses L and N terminals.
### Which Wi-Fi band and modes are supported?
The device supports IEEE 802.11 b/g/n at 2.412–2.472 GHz in STA, AP, or AP+STA modes. AP and STA must use different IP subnets. In AP+STA mode, keep STA connected to a router to avoid scanning-related AP disruption.
### Is Bluetooth limited to network provisioning?
No. BLE 5.0 supports app-based BLE provisioning and bidirectional Bluetooth–serial data transmission.
### Does it convert Modbus RTU and Modbus TCP?
Yes. It supports bidirectional Modbus TCP and Modbus RTU conversion, timed acquisition, and data format conversion.
### Which serial settings are documented?
7 or 8 data bits, 1 or 2 stop bits, None/Even/Odd parity, and software Xon/Xoff. The baud-rate row is labeled TTL: 1200–230400 bps; applicability to the external serial interface requires confirmation. There is no hardware flow control.
### How is the device configured and updated?
Use the web interface, serial CLI, XML import, Telnet, companion configuration software, or app-based Wi-Fi or BLE provisioning. Firmware updates are available through the web interface, companion configuration software, and wireless OTA.
### How do I reset it and mount it?
Hold Reload for more than 4 seconds and release to restore factory settings. Reset performs a hardware reset. The 102.03 × 64.95 × 27.50 mm enclosure mounts on a C45 guide rail.

## Related

- [Wi-Fi](https://www.iiotsys.net/technologies/wi-fi)
- [RS-485/RS-232](https://www.iiotsys.net/technologies/rs-485rs-232)
- [Modbus RTU/TCP](https://www.iiotsys.net/technologies/modbus-rtutcp)
- [MQTT](https://www.iiotsys.net/technologies/mqtt)
- [DIN Rail Mount](https://www.iiotsys.net/technologies/din-rail-mount)
- [Bluetooth](https://www.iiotsys.net/technologies/bluetooth)