# PG41-DC RS485 4G LTE Serial Device Server (DC Power)

> DC-powered RS485 4G LTE serial device server for remote monitoring of industrial serial equipment.

- **URL**: https://www.iiotsys.net/products/pg41-dc-rs485-4g-lte-serial-device-server-dc-power
- **Markdown**: https://www.iiotsys.net/products/pg41-dc-rs485-4g-lte-serial-device-server-dc-power.md
- **Model**: PG41-DC
- **SKU**: IIS-SG-PG41-DC
- **Price**: $27.00 USD
- **Category**: Industrial Gateways & Serial Servers

## Overview

The IIoTSys PG41-DC connects one RS485 serial interface to a cellular network through a LTE Cat.1 module. It is intended for remote monitoring of industrial serial equipment, sensors, controllers, and data acquisition systems. This DC-powered model accepts 9–48 VDC @ 1 A. A Cortex-M3 processor runs at 96 MHz with the FreeRTOS operating system.

The 4G band option combines LTE-FDD and LTE-TDD bands in one selection: B1 / B3 / B5 / B8 / B34 / B38 / B39 / B40 / B41. Check the bands against the intended mobile operator before deployment. The device uses a Nano SIM card with 1.8 V or 3 V support and has an SMA cellular antenna connector. The band selection identifies the supported 4G radio bands, rather than a guaranteed connection on every network.

Network working modes include transparent transmission, HTTP, MQTT, and WebSocket. The device supports a maximum of 3 TCP or UDP connections, with a 1400-byte data cache for each connection. Modbus TCP to Modbus RTU conversion connects a network-side Modbus application with serial equipment. NTP support provides a network time function. These functions cover serial networking and protocol integration without requiring a change to the equipment's serial interface.

Serial framing includes 7 or 8 data bits, 1 or 2 stop bits, and None, Even, or Odd parity. Software flow control is specified. Connect A+ to A+ and B− to B−. A shared GND connection is recommended under severe interference. The RS485 interface operates in half-duplex mode. It supports up to 32 devices and a maximum cable length of 1200 m. The installation instructions call for 120 Ω termination when cable length exceeds 300 m.

Configuration is available through serial AT commands, SMS AT commands, and companion configuration software over the serial or network connection. Registration packets and heartbeat packets can combine ICCID, IMEI, IMSI, software version, and cellular connection status. Firmware updates are available through the serial port and network OTA. These functions support setup and maintenance of deployed serial devices.

The enclosure measures 102.03 × 64.95 × 27.50 mm and mounts on a C45 guide rail. Operating temperature is −40 to +70 °C. Storage conditions are −40 to +85 °C and 5–95% RH without condensation. Net, Active, Power, and Link indicators show network, serial activity, power, and server connection status. Reload restores factory settings, while Reset performs a hardware reset.

## Description

RS485-to-4G LTE serial device server with a LTE Cat.1 module and 9–48 VDC @ 1 A input. Supports transparent transmission, HTTP, MQTT, WebSocket, and Modbus TCP to Modbus RTU conversion.

## Specifications

- Model: PG41-DC
- SKU: IIS-SG-PG41-DC
- Product type: RS485-to-4G LTE serial device server
- Cellular module: LTE Cat.1
- 4G bands: B1 / B3 / B5 / B8 / B34 / B38 / B39 / B40 / B41
- Processor: Cortex-M3, 96 MHz
- Operating system: FreeRTOS
- Serial interface: 1 × RS485
- Serial wiring: Connect A+ to A+ and B− to B−. A shared GND connection is recommended under severe interference.
- Baud rate: TTL: 1200–460800 bps
- Data bits: 7 / 8
- Stop bits: 1 / 2
- Parity: None / Even / Odd
- Flow control: Software flow control
- RS485 duplex: Half-duplex
- RS485 terminals: Pin 5: B−; pin 6: GND; pin 7: A+
- RS485 bus capacity: Maximum 32 devices
- RS485 cable length: Maximum 1200 m
- RS485 termination: 120 Ω termination for cable lengths over 300 m
- Working modes: Network transparent transmission / HTTP / MQTT / WebSocket
- TCP/UDP connections: Maximum 3 connections; 1400-byte data cache per connection
- Modbus conversion: Modbus TCP to Modbus RTU
- Time synchronization: NTP
- SIM card: Nano SIM, 1.8 V / 3 V
- Antenna connector: SMA cellular antenna connector
- Configuration: Serial AT commands; SMS AT commands; companion serial or network configuration software
- Registration and heartbeat packets: Can combine ICCID, IMEI, IMSI, software version, and cellular connection status
- Firmware update: Serial port and network OTA
- Power input: 9–48 VDC @ 1 A
- Average working current: Approximately 80 mA at 12 VDC; not an AC mains-current rating
- Peak current: 2 A; test conditions are not specified
- Dimensions: 102.03 × 64.95 × 27.50 mm (L × W × H)
- Mounting: C45 guide rail
- Operating temperature: −40 to +70 °C
- Storage conditions: −40 to +85 °C; 5–95% RH, non-condensing
- Indicators: Net / Active / Power / Link
- Factory reset: After power-up, hold Reload for more than 3 seconds and release
- Hardware reset: Reset button
- EMC: Class B, as stated in the manual; no certification claim

## Protocols

- 4G LTE (native): LTE Cat.1; B1 / B3 / B5 / B8 / B34 / B38 / B39 / B40 / B41
- RS485 (native): One serial interface. Connect A+ to A+ and B− to B−. A shared GND connection is recommended under severe interference.
- TCP (native): TCP connections for serial networking
- UDP (native): UDP connections for serial networking
- HTTP (native): HTTP working mode
- MQTT (native): MQTT working mode
- WebSocket (native): WebSocket working mode
- NTP (native): Network time support
- Modbus TCP to Modbus RTU (convert): Converts Modbus TCP to Modbus RTU.

## Features

- One RS485 interface; 9–48 VDC @ 1 A input
- Half-duplex RS485; up to 32 devices and 1200 m cable length; 120 Ω termination over 300 m
- LTE Cat.1 with one combined LTE-FDD and LTE-TDD band option
- Cortex-M3 processor at 96 MHz; FreeRTOS
- Transparent transmission, HTTP, MQTT, and WebSocket working modes
- Maximum 3 TCP/UDP connections with a 1400-byte cache for each connection
- Modbus TCP to Modbus RTU conversion; NTP
- Nano SIM supporting 1.8 V and 3 V; SMA cellular antenna connector
- Serial AT, SMS AT, and companion software configuration
- Registration and heartbeat packets with device and connection information
- Serial and network OTA firmware updates
- 7/8 data bits; 1/2 stop bits; None/Even/Odd parity; software flow control
- C45 guide-rail mounting; −40 to +70 °C operation

## Use cases

- Remote monitoring of serial equipment
- Industrial sensor and controller networking
- Production asset tracking and monitoring
- Data acquisition equipment connectivity
- UPS power management equipment networking

## FAQ

### Which serial interface does the PG41-DC provide?
It has one RS485 interface. PG40 is the RS232 version and PG41 is the RS485 version. Connect A+ to A+ and B− to B−. A shared GND connection is recommended under severe interference.
### Which power supply does this model require?
The PG41-DC accepts 9–48 VDC @ 1 A. Observe the positive and negative DC input polarity. The 1 A notation is the specified input rating, not measured operating consumption.
### Which 4G bands are included in the option?
The LTE Cat.1 option includes B1 / B3 / B5 / B8 / B34 / B38 / B39 / B40 / B41. LTE-FDD and LTE-TDD bands are combined in one selection. Check compatibility with the intended operator before deployment.
### What SIM card does it use?
It uses a Nano SIM card and supports 1.8 V and 3 V SIM operation.
### Does it support Modbus and other network modes?
It supports Modbus TCP to Modbus RTU conversion. Working modes include network transparent transmission, HTTP, MQTT, and WebSocket. A maximum of 3 TCP/UDP connections is supported, each with a 1400-byte cache.
### How is it mounted, and what are its environmental limits?
The 102.03 × 64.95 × 27.50 mm enclosure mounts on a C45 guide rail. Operating temperature is −40 to +70 °C. Storage conditions are −40 to +85 °C and 5–95% RH without condensation.
### Which serial framing and baud settings are documented?
Serial framing supports 7 or 8 data bits, 1 or 2 stop bits, and None, Even, or Odd parity. Software flow control is specified. The baud range is labeled TTL: 1200–460800 bps.
### How is the device configured and updated?
Use serial AT commands, SMS AT commands, or companion configuration software over the serial or network connection. Firmware updates are available through the serial port and network OTA. After power-up, hold Reload for more than 3 seconds and release to restore factory settings. Reset performs a hardware reset.

## Related

- [4G LTE](https://www.iiotsys.net/technologies/4g-lte)
- [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)