# 4-Ch RS485 to RJ45 Ethernet Serial Server (Isolated, Rail-Mount)

**Type:** Product page · **SKU:** WS-26360 · **Brand:** [Waveshare](https://core-electronics.com.au/brands/waveshare-in-australia)
**Page:** https://core-electronics.com.au/4-ch-rs485-to-rj45-ethernet-serial-server-isolated-rail-mount.html ([markdown](https://core-electronics.com.au/4-ch-rs485-to-rj45-ethernet-serial-server-isolated-rail-mount.html.md))

Bridge four isolated RS485 buses onto one network cable, with Modbus and MQTT gateway modes built in.

## Pricing

- **Price:** $89.63 (inc GST) — $81.48 AUD, exc GST

## Availability & dispatch

- Available with a lead time — expect dispatch between Aug 24 and Aug 31.

## Description

Four independent RS485 channels, each receiving and transmitting at the same time, bridged onto a single 10/100M Ethernet drop.

Adding more field devices to a single-port serial server means sharing one bus, arbitrating turns and living with collisions. Here each channel carries its own traffic in parallel, so a slow energy meter on one port cannot stall a PLC on another.

Onboard power and signal isolation, TVS suppression, a resettable fuse and protection diodes keep the network side and the field side apart — the protection that matters when RS485 runs the length of a plant. The RJ45 adds 2 KV surge protection, and the sand-blasted anodised aluminium enclosure clips to DIN rail or bolts to a wall.

Beyond transparent transmission it operates as a Modbus gateway, an MQTT gateway and an RS485-to-JSON acquisition gateway, all configurable from a web browser. Multi-host roll-polling identifies and answers each network device separately, and DHCP, DNS and NTP are supported.

### Features

- Runs four RS485 buses concurrently without arbitration — each channel receives and transmits independently, so added devices do not slow the ones already there
- Survives noisy industrial wiring thanks to onboard power and signal isolation, built-in TVS suppression, a resettable fuse and protection diodes, plus 2 KV surge protection on the Ethernet port
- Accepts a wide DC 6–45 V input through a screw terminal that stays put under vibration, unlike a barrel jack
- Replaces a separate gateway appliance: serial server, Modbus gateway, MQTT gateway and RS485-to-JSON conversion in a single unit
- Publishes straight to cloud brokers over MQTT or HTTP POST/GET, with user-defined heartbeat and registration packets for device identification
- Answers several network hosts separately, removing the crosstalk you get when multiple masters poll the same field devices
- Deploys in minutes on DIN rail or wall mount in a sand-blasted, anodised aluminium enclosure measuring 91 × 64.5 × 24.2 mm
- Keeps working from −40 °C to 85 °C, suiting unconditioned cabinets and outdoor enclosures

### Specifications

| Property | Specification |
|---|---|
| Product type | Serial server, Modbus gateway, MQTT gateway |
| Serial ports | 4 × isolated RS485, independent simultaneous receive and transmit |
| Ethernet | RJ45, 10/100M auto-negotiation, 2 KV surge protection (no PoE on this version) |
| Isolation | Power isolation and signal isolation |
| Power input | DC 6–45 V via screw terminal |
| Baud rate | 300–115200 bps |
| Data bits | 5–9 bits |
| Parity | None, odd, even, mark, space |
| Protocols | Ethernet, IP, TCP, UDP, HTTP, ARP, ICMP, DHCP, DNS |
| Operating modes | TCP server, TCP client (coexisting with TCP server), UDP, UDP multicast |
| Configuration | Host software, web browser, device management function library |
| Operating temperature | −40 °C to 85 °C |
| Humidity | 5–95% relative humidity |
| Dimensions | 91.0 × 64.5 × 24.2 mm |
| Weight | 187 g |

### Resources

- [Waveshare Wiki — 4-CH RS485 TO ETH (B)](https://www.waveshare.com/wiki/4-CH_RS485_TO_POE_ETH_(B))

### What's Included

- 1x 4-Ch RS485 to RJ45 Ethernet Serial Server
- 1x Rail-mount buckle
- 1x Screwdriver
- 1x Screws pack

## Images

- [Product image 1](https://core-electronics.com.au/media/catalog/product/W/S/WS-26360_ecommerce_1785815053941.jpg)