# SLZB-xxU and ZWA-2

## ✅ Using ZWA-2 Z-Wave Dongle with SLZB-MR1U via USB Passthrough

[![SLZB-MR1U-and-ZWA-2-connection.jpg](https://smlight.tech/support/manuals/uploads/images/gallery/2025-08/scaled-1680-/slzb-mr1u-and-zwa-2-connection.jpg)](https://smlight.tech/support/manuals/uploads/images/gallery/2025-08/slzb-mr1u-and-zwa-2-connection.jpg)

### Overview

Many users asked whether the **ZWA-2 Z-Wave USB stick** can be used with the **SLZB-MR1U** using its **USB passthrough over Ethernet** feature.

Until recently, we couldn’t confirm, as it hadn’t been tested in-house.

We have now completed testing and can confirm:

✅ **ZWA-2 works with SLZB-MR1U using USB passthrough.**

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### Requirements

- SLZB-MR1U hardware
- SLZB-OS firmware v3.0.0 or newer
- ZWA-2 USB Z-Wave stick
- Z-Wave JS UI (or other TCP-compatible Z-Wave host)
- Network access to the SLZB-MR1U IP address

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### Why SLZB-OS v3.0.0?

Firmware **v3.0.0** (released 29 August 2025) is required because it:

✅ Resolves **USB passthrough instability**  
✅ Fixes **EFR32 firmware update failures**  
✅ Improves overall SLZB-MR1U reliability

You can update via:

- OTA (if available)
- Manual update via USB-C and our Web Flasher:  
    ➡️ [https://smlight.tech/flasher/#SLZB-06U-MRxU<span aria-hidden="true" class="ms-0.5 inline-block align-middle leading-none"><svg class="block h-[0.75em] w-[0.75em] stroke-current stroke-[0.75]" data-rtl-flip="" fill="currentColor" height="20" viewbox="0 0 20 20" width="20" xmlns="http://www.w3.org/2000/svg"><path d="M14.3349 13.3301V6.60645L5.47065 15.4707C5.21095 15.7304 4.78895 15.7304 4.52925 15.4707C4.26955 15.211 4.26955 14.789 4.52925 14.5293L13.3935 5.66504H6.66011C6.29284 5.66504 5.99507 5.36727 5.99507 5C5.99507 4.63273 6.29284 4.33496 6.66011 4.33496H14.9999L15.1337 4.34863C15.4369 4.41057 15.665 4.67857 15.665 5V13.3301C15.6649 13.6973 15.3672 13.9951 14.9999 13.9951C14.6327 13.9951 14.335 13.6973 14.3349 13.3301Z"></path></svg></span>](https://smlight.tech/flasher/?utm_source=chatgpt.com#SLZB-06U-MRxU)

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### Setup Instructions

1. Flash SLZB-MR1U with **SLZB-OS v3.0.0**
2. Enable USB passthrough option (Go to [http://slzb-mr1u.local/usb](http://slzb-mr1u.local/usb)) [![image.png](https://smlight.tech/support/manuals/uploads/images/gallery/2025-08/scaled-1680-/DQJimage.png)](https://smlight.tech/support/manuals/uploads/images/gallery/2025-08/DQJimage.png)
3. Plug the **ZWA-2 USB stick** into the USB-A port - right out of the box.
4. Open **Z-Wave JS UI** on your smart home host
5. Go to **Settings** -&gt; **Z-Wave** -&gt; **Serial port** and Set the serial port to:
    
    <div class="contain-inline-size rounded-2xl relative bg-token-sidebar-surface-primary"><div class="sticky top-9"></div><div class="overflow-y-auto p-4" dir="ltr">`tcp:<span class="hljs-comment">//<SLZB-MR1U-IP>:8638</span>`where `<span class="hljs-comment"><SLZB-MR1U-IP></span>` is an actual IP address of your SLZB-MR1 in your network.</div></div>
6. Save settings and restart the service, if asked.
    
    [![image.png](https://smlight.tech/support/manuals/uploads/images/gallery/2025-08/scaled-1680-/Nu6image.png)](https://smlight.tech/support/manuals/uploads/images/gallery/2025-08/Nu6image.png)
7. Pair Z-Wave devices as usual (we did it via Z-Wave integration).

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### ⚠️ Notes &amp; Best Practices

- One USB device is supported at the moment via USB passthorugh.
- Ensure port **8638** is accessible on your LAN

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### Troubleshooting

<div class="_tableContainer_1rjym_1" id="bkmrk-problem-solution-zwa"><div class="_tableWrapper_1rjym_13 group flex w-fit flex-col-reverse" tabindex="-1"><table class="w-fit min-w-(--thread-content-width)" data-end="2553" data-start="2013"><thead data-end="2121" data-start="2013"><tr data-end="2121" data-start="2013"><th data-col-size="sm" data-end="2046" data-start="2013">Problem</th><th data-col-size="md" data-end="2121" data-start="2046">Solution</th></tr></thead><tbody data-end="2553" data-start="2230"><tr data-end="2338" data-start="2230"><td data-col-size="sm" data-end="2263" data-start="2230">ZWA-2 not detected</td><td data-col-size="md" data-end="2338" data-start="2263">Confirm IP and port, check firmware is v3.0.0 or newer</td></tr><tr data-end="2446" data-start="2339"><td data-col-size="sm" data-end="2371" data-start="2339">Devices won’t pair</td><td data-col-size="md" data-end="2446" data-start="2371">Restart Z-Wave JS UI after configuring the serial port</td></tr><tr data-end="2553" data-start="2447"><td data-col-size="sm" data-end="2479" data-start="2447">Unstable USB connection</td><td data-col-size="md" data-end="2553" data-start="2479">Use a shorter or higher-quality USB cable (or powered USB hub)</td></tr></tbody></table>

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