> **Source:** Core Electronics is an Australian maker-electronics retailer and manufacturer based in Newcastle, NSW, run by a team of makers and educators. We design and manufacture our own product lines (PiicoDev, CE originals) and are official retailers for iconic maker and industrial brands including Raspberry Pi, Arduino, Adafruit, SparkFun and DFRobot. Orders ship Australia-wide from our Newcastle warehouse. Prices are in AUD and include GST. Pricing, stock and dispatch on this page are generated from the store's live catalog. Full machine-readable index: https://core-electronics.com.au/llms.txt # 8-ch Ethernet Relay Module (B) **Type:** Product page · **SKU:** WS-27876 · **Brand:** [Waveshare](https://core-electronics.com.au/brands/waveshare-in-australia) **Page:** https://core-electronics.com.au/8-ch-ethernet-relay-module-modbus-poe-industrial.html ([markdown](https://core-electronics.com.au/8-ch-ethernet-relay-module-modbus-poe-industrial.html.md)) 8-ch Ethernet Relay Module (B) With Digital Input, Modbus RTU/Modbus TCP Protocol, PoE Port Communication, With Various Isolation And Protection Circuits,... ## Pricing - **Price:** $76.35 (inc GST) — $69.41 AUD, exc GST - **Quantity discounts:** 6+ $66.64 (exc GST) · 12+ $64.55 (exc GST) ## Availability & dispatch - In stock, ships same business day if ordered before 2PM (Australia/Sydney). - We can dispatch 8 today, and up to 300 more in 12–19 days. ## How to buy - **Build a cart:** compose `https://core-electronics.com.au/cart/link?items=WS-27876:1` (comma-separated SKU:qty pairs) and share the link. Opening it shows a confirmation page with live pricing and stock before anything is added to the cart. - **Verify the cart first:** fetch `https://core-electronics.com.au/cart/link/WS-27876:1.md` for live line prices (inc & exc GST, quantity discounts applied), stock and dispatch estimates, and totals. Append `/to/{AU-postcode}` (or `/to/{country-code}:{postcode}`) before `.md` for delivery options and prices to that destination. Unknown, retired, or out-of-stock SKUs are flagged. (Query form `cart/link.md?items=...` also works but some robots parsers refuse query strings here.) - **Checkout** is completed on-site and includes a captcha at the payment step. Share the cart link; checkout takes it from there. - **Search the catalogue:** `https://core-electronics.com.au/search/{query}.md` (URL-encode the query; pages 2-3 at `search/{query}/{page}.md`; `search.md?q=` also works) - **Payment methods, purchase orders, policies and contact details:** https://core-electronics.com.au/llms.txt ## Description The 8-channel Ethernet Relay Module (B) is an industrial-grade relay module controlled via Ethernet with 8 digital inputs. It supports Modbus RTU/Modbus TCP protocols, features PoE power supply, and comes in an ABS rail-mount case for easy installation and industrial use. ### Features This product offers robust functionality for industrial control equipment, providing fast communication, stability, and reliability. Key features include: - Flash-on, flash-off function for timed relay activation. - Supports DC 7~36V wide-range power input and PoE power supply. - MQTT protocol relay control with Alibaba Cloud MQTT application demo. - Optocoupler isolation to prevent high-voltage circuit interference. - Dedicated relay driver chip with built-in flyback diode protection. - Passive and active digital input support with bi-directional optocoupler isolation and debouncing algorithm. - Reverse-proof circuit for accidental connection protection. - High-quality relay with contact rating: =10A 250VAC/30VDC. - Rail-mounted ABS plastic enclosure for easy installation and safety. - LED and network indicators for monitoring MCU status and signal transmission. ### Primary Function The module supports reading digital inputs via Modbus RTU protocol commands sent through Ethernet to control relay outputs. ![8-ch Ethernet Relay Module (B), primary function](https://core-electronics.com.au/attachments/localcontent/Modbus-POE-ETH-Relay-B-details-3_14225e46010.jpg)### Communication Modes The module supports various communication modes: - TCP Server - TCP Client - UDP Mode - UDP Multicast - HTTP - MQTT It is compatible with Modbus RTU and Modbus TCP protocols. ![8-ch Ethernet Relay Module (B), Modbus protocol support](https://core-electronics.com.au/attachments/localcontent/Modbus-POE-ETH-Relay-B-details-4_6783504ac99.jpg)### Configuration Methods Supports configuration through software or a web browser, with dynamic IP assignment via DHCP and domain name connection through DNS protocol. ![8-ch Ethernet Relay Module (B), multi-configuration methods](https://core-electronics.com.au/attachments/localcontent/Modbus-POE-ETH-Relay-B-details-7_188953acad8.jpg)### Power Supply Options The module offers multiple power supply options: - DC power port with plug support. - Screw terminal for DC 7~36V input. - PoE port compliant with IEEE 802.3af standards. \*External power supply adapter is not included. A [12V power supply](https://core-electronics.com.au/ord-psu-12v2a-5.5-2.1.htm) is recommended if needed. ![8-ch Ethernet Relay Module (B), power supply options](https://core-electronics.com.au/attachments/localcontent/Modbus-POE-ETH-Relay-B-details-9_11081fb12e5.jpg)### Digital Input Supports passive (dry contact) and active (wet contact) digital inputs with bi-directional optocoupler isolation. ![8-ch Ethernet Relay Module (B), digital input demo](https://core-electronics.com.au/attachments/localcontent/Modbus-POE-ETH-Relay-B-details-11_17649fa73fc.jpg)### Interfaces & Indicators The module includes multiple LED indicators for easy monitoring: | RUN | Blinks when the Ethernet port is operating normally. | |---|---| | STA | Blinks when the MCU is functioning correctly. | | TXD | Lights up during data transmission. | | RXD | Lights up during data reception. | | Ethernet Port Green Indicator | Indicates Ethernet connectivity status. | ![8-ch Ethernet Relay Module (B), interface and indicator details](https://core-electronics.com.au/attachments/localcontent/Modbus-POE-ETH-Relay-B-details-13_26614801376.jpg)### Dimensions ### ![](https://core-electronics.com.au/media/wysiwyg/Modbus-POE-ETH-Relay-B-details-size.jpg) ### Resources - [Wiki for 8-ch Ethernet Relay Module (B)](https://www.waveshare.com/wiki/Modbus_POE_ETH_Relay_(B)) ## Images - [Product image 1](https://core-electronics.com.au/media/catalog/product/W/S/WS-27876-1.jpg)