USB TO RS485 (E)
USB TO RS485 (E) is an industrial-grade isolated USB-to-RJ45 single-channel RS485 converter, featuring the FT232RNL chip and an isolated RS485 transceiver circuit. The USB side uses a USB-A plug, and the RS485 side uses an RJ45 female socket, which accepts cables or adapters with RJ45 male connectors.
The RJ45 interface follows T568B pinout and carries RS485 signals plus auxiliary power. It is not an Ethernet interface.
| SKU | Product |
|---|---|
| 35226 | USB TO RS485 (E) |
Features
- Supports bidirectional communication between USB and a single RS485 channel, with hardware automatically controlling data transmit/receive direction
- Uses the FT232RNL USB-to-UART chip
- Isolated RS485 transceiver integrates signal isolation and isolated power supply
- Transient surge and ESD protection circuits on both USB and RS485 sides, rated for 600 W lightning surge protection
- Onboard TVS, ESD protection devices, resettable fuse, and protection diodes
- Onboard fixed 120 Ω termination resistor
- RJ45 interface provides 5 V auxiliary power output, maximum output current 100 mA
- Equipped with TXD and RXD status indicators
- Supports Windows, macOS, Linux, Android, and WinCE
Product Specifications
| Parameter | Description |
|---|---|
| Product Type | Industrial-grade isolated USB-to-RJ45 single-channel RS485 converter |
| Communication Chip | FT232RNL |
| Communication Rate | 300 bps - 512000 bps |
| Host Interface | USB-A, 5 V operating level |
| Device Interface | RJ45 female socket, single-channel RS485, T568B pinout |
| RS485 Pinout | 1=A, 2=B, 3=NC, 4=5 V, 5=5 V, 6=NC, 7=GND, 8=GND |
| Auxiliary Power Output | 5 V, maximum output current 100 mA |
| Direction Control | Hardware automatically determines and controls data transmission direction |
| RS485 Nodes | Point-to-multipoint communication, up to 32 nodes; a repeater is recommended when exceeding 16 nodes |
| RS485 Transmission Distance | Approximately 1200 m (at low baud rates and with ideal cable conditions) |
| USB Transmission Distance | Approximately 5 m |
| Termination Matching | Onboard fixed 120 Ω termination resistor |
| Isolation Method | Isolated RS485 transceiver with integrated signal isolation and isolated power supply |
| Indicators | TXD transmit indicator (green), RXD receive indicator (yellow) |
| Enclosure Size | Approx. 61.5 mm × 22.9 mm × 15.1 mm, excluding USB-A plug |
| Operating Temperature | -40°C - 85°C |
| Operating Humidity | 5% RH - 95% RH |
| Operating Systems | Windows 11 / 10 / 8.1 / 8 / 7 / XP, macOS, Linux, Android, WinCE |
Appearance and Connection
The product features a black straight-plug enclosure with a USB-A plug on one end and an RJ45 female socket on the other. The RXD and TXD indicators are located next to the RJ45 socket. Connect the USB-A end to the host, and connect the RJ45 female socket to a cable with an RJ45 male plug; the other end of the cable should be wired according to the target RS485 device's pinout.
The RJ45 form factor does not imply Ethernet protocol. A standard straight-through patch cable only ensures pin-to-pin continuity — it does not guarantee that the signal definitions on the peer device match those of this product.
RJ45 Pinout
RJ45 pinout reference
| Pin | T568B Color | Signal | Description |
|---|---|---|---|
| 1 | White/Orange | A | RS485 differential signal A+ |
| 2 | Orange | B | RS485 differential signal B- |
| 3 | White/Green | NC | Not connected |
| 4 | Blue | 5 V | 5 V auxiliary power output |
| 5 | White/Blue | 5 V | 5 V auxiliary power output |
| 6 | Green | NC | Not connected |
| 7 | White/Brown | GND | Power ground and RS485 reference ground |
| 8 | Brown | GND | Power ground and RS485 reference ground |
The table follows RJ45 contact numbering. When inspecting the socket or making a cable, always refer to the pin markings on the connector and the crimped plug — do not rely solely on visual orientation.
This interface does not support Ethernet. Do not connect it to a switch, router, or any Ethernet port. If the peer device does not use the power pins, leave pins 4 and 5 disconnected. When using the 5 V auxiliary power, the load current must not exceed 100 mA.
Indicator Descriptions
| LED Indicator | Status Description |
|---|---|
| RXD | Yellow LED flashes when data is returned from the RS485 device side |
| TXD | Green LED flashes when data is being sent from the USB side |
Isolation and Protection
The product uses an RS485 transceiver that integrates signal isolation and an isolated power supply. The USB side and RS485 side are equipped with TVS, ESD protection devices, a self-recovery fuse, and protection diodes to suppress the effects of transient surges, electrostatic discharge, overcurrent, and overvoltage on the interfaces. Isolation and protection circuits do not replace on-site grounding, shielding, or lightning protection measures.
Product Dimensions
The 61.5 mm dimension shown is the enclosure length, excluding the USB-A plug.
