ISO-USB2RS485
Industrial Isolated USB to RS485 Communication Converter Module
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Isolated USB to RS485 Converter Module
| Galvanic Isolation: | Texas Instruments ISO3088 (2.5 kVrms) |
| ESD Protection: | Up to 15 kV ESD + TVS Diode Network |
| USB-UART Bridge: | Silicon Labs CP2102N (300 bps – 3 Mbps) |
| Bus Termination: | Switch-Selectable 120 Ω Resistor |
| Supply Voltage: | 5V DC (USB Bus-Powered, No External PSU Required) |
| Connectors: | Mini-USB Socket & 3-Pin Screw Terminal (A+, B-, GND) |
| LED Indicators: | PWR (Power), TX (Transmit), RX (Receive) |
| Enclosure: | Transparent Top Cover with Protective Housing |
Product Overview
Engineered and manufactured by PMT Electronics, the ISO-USB2RS485 Isolated USB to RS485 Converter is a high-reliability hardware module designed to interface standard USB ports with industrial RS485 networks, PLCs, smart meters, motor drives, and field sensors.
Galvanic Isolation Architecture: Featuring the industry-standard Texas Instruments ISO3088 isolated half-duplex transceiver, the module provides a certified 2.5 kVrms component isolation barrier between the computer and the RS485 field network. This eliminates ground loop currents caused by earth potential differences between distant nodes, suppresses common-mode noise, and prevents dangerous industrial surges or transient spikes from damaging connected computers.
Comprehensive 15 kV ESD Protection: Integrated TVS diode arrays on both USB and RS485 interfaces deliver robust electrostatic discharge resistance up to 15 kV. The transparent top cover allows instant visual inspection of the hardware status and LEDs while safeguarding the circuitry in demanding factory floor environments.
Key Features & Highlights
2.5 kVrms Galvanic Isolation
Certified TI ISO3088 isolation barrier prevents ground loops and safeguards host computers against catastrophic industrial electrical faults.
15 kV ESD Protection
High-speed TVS diode arrays shield USB lines and RS485 differential lines from electrostatic discharge and transient voltage spikes.
Selectable 120 Ω Termination
Onboard slide switch enables or disables the 120 Ω bus line termination resistor instantly without needing external resistors or soldering.
Silicon Labs CP2102N
High-performance USB-to-UART bridge supports data transmission speeds from 300 bps to 3 Mbps (3 Mbaud) with low latency.
Active Status LEDs
Individual LEDs for Power (PWR), Transmit (TX), and Receive (RX) offer instant real-time diagnostics of serial bus activity.
Bus Powered (5V USB)
Draws power directly from the USB host. Generates its own isolated DC power supply internally with no bulky power bricks required.
Clear Top Housing
Rugged, compact protective enclosure with a transparent top cover combines physical protection with full PCB and LED visibility.
Multi-OS Compatibility
Fully compatible with Windows 11/10/8/7, Linux kernels 2.6+, and macOS. Works with standard serial communication software.
Hardware Architecture & Wiring Guide
RS485 Terminal Pinout
Always disconnect field power before wiring. Match pins according to the PCB silk-screen label:
| Terminal | Signal Type | Description |
|---|---|---|
| A+ | Differential (+) | RS485 Non-Inverting differential line (D+). |
| B- | Differential (-) | RS485 Inverting differential line (D-). |
| GND | Isolated Ground | RS485 isolated signal reference ground. Do not bridge to computer USB GND. |
120 Ω Bus Termination & Diagnostics
120 Ω Termination Switch Rule
To prevent reflections on the RS485 transmission line, termination resistors must only be enabled at the two physical ends of the bus:
- Endpoint Device: Set the switch to ON to enable the onboard 120 Ω resistor.
- Intermediate Drop / Tap: Keep the switch OFF to avoid overloading the bus.
Diagnostic LEDs
Technical Specifications
| Parameter | Specification / Value |
|---|---|
| Model / SKU | ISO-USB2RS485 / HBCV0000KDWMR4 |
| Manufacturer | PMT Electronics • Turkey |
| Galvanic Isolation Rating | 2.5 kVrms (60-second component test rating, Texas Instruments ISO3088) |
| ESD Protection | Up to 15 kV ESD protection with TVS diode suppression networks |
| USB-UART Bridge IC | Silicon Labs CP2102N (Virtual COM Port) |
| RS485 Transceiver IC | Texas Instruments ISO3088 (Galvanically isolated, half-duplex) |
| Baud Rates | 300 bps to 3,000,000 bps (3 Mbps) continuous range |
| Bus Termination | Built-in 120 Ω resistor with slide switch activation |
| Operating Voltage | 4.5 V – 5.25 V DC (Powered via USB port) |
| Field Terminal | 3-pin screw terminal block: A+ (D+), B- (D-), GND (Isolated Ground) |
| USB Interface | Mini-USB socket (30 cm USB-A to Mini-USB cable included) |
| Visual Indicators | 3 Status LEDs: Power (PWR), Transmit (TX), Receive (RX) |
| Dimensions | 61 × 32 × 15 mm compact form factor |
| Housing | Transparent protective cover with durable polymer base |
| Supported Protocols | Modbus RTU, Modbus ASCII, BACnet MS/TP, DMX512, custom RS485 protocols |
| Operating Systems | Windows 11, 10, 8.1, 8, 7; Linux (Kernel 2.6+); macOS; Android |
| Driver Support | Silicon Labs CP210x VCP drivers (Plug-and-play in modern OS) |
| Warranty | 24-Month Official PMT Warranty |
Package Contents
1x PMT Isolated USB to RS485 Converter Module
Housed in transparent protective casing, tested and ready to deploy.
1x USB-A to Mini-USB High-Quality Cable (30 cm)
High-speed data transfer and power delivery cable.
Official User Manual & Engineering Support
Detailed 10-page wiring, setup, and troubleshooting manual (PDF).
Documentation & Drivers
Downloadable Resources
Access the official 10-page guide for setup, terminal schematics, and recommended terminal settings:
Applications & Use Cases
Frequently Asked Questions
Protect Your Industrial Communications
Upgrade to the PMT Isolated USB to RS485 Converter Module and safeguard your computers and control equipment with verified galvanic isolation.