#28 in Industrial Control (B2B)

Waveshare Modbus RTU Relay Module 8 Channels (RS485, Industrial)

Name: Waveshare Modbus RTU Relay Module 8 Channels (RS485, Industrial)
SKU: B083J24HCM
Price: 41.99 USD
Availability: InStock
Rating: 4.8 (28 reviews)

4.8(28 reviews)

$41.99reference price

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Best for

Small installations (up to 8 outputs) where the 16- or 32-channel modules in this ranking would be an unnecessary expense.

8 channels
RS485 Modbus RTU
Optical isolation

What is it and what's it for?

It is the smallest version of the same family of Modbus RTU relay modules in this ranking — same RS485 protocol, same electrical protections, but with 8 outputs instead of 16 or 32, for projects that do not need that much capacity.

Real-world use cases

At home

A small DIY home-automation project — for example, controlling irrigation, a couple of outdoor lights, and a gate — that does not justify paying for 16 or 32 channels you will not use.

In a business or workshop

A small control panel on a production line or equipment room that only needs to switch 8 different devices over Modbus, without oversizing the system.

How to avoid buying the wrong one

It has 28 real reviews (4.8 stars) — unlike the 16- and 32-channel modules in this ranking, which do not have any reviews on Amazon yet.
The listing does not state the supply voltage range (other Waveshare modules in this family use DC 7-36V) — confirm it with the seller before buying if your power source is fixed.
Includes a timed on/off function (flash-on/flash-off) by command, useful for activating a relay for a fixed time without extra logic in the controller.

The investment takeaway

At $41.99 it costs more per channel than the 16-channel module in this ranking ($63.35÷16 ≈ $3.96/channel vs. $41.99÷8 ≈ $5.25/channel), but it is the only one of the three with a real buyer track record — if your installation is small and you would rather not be the first to try a module with no reviews, the extra cost per channel is justified.

Waveshare Modbus RTU Relay Module 8 Channels (RS485, Industrial)

$41.99reference price

See current price on Amazon

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