SLZB-xxU and ZWA-2

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

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 were unable to confirm this — as it had not been tested in-house.

We have now tested this setup, and we can confirm:

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

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???? What You Need

• SLZB-MR1U hardware

• SLZB-OS firmware v3.0.0 or newer

• ZWA-2 USB Z-Wave stick

• Z-Wave JS UI (or compatible integration)

• Access to the SLZB-MR1U's IP address on your local network

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???? Why SLZB-OS v3.0.0?

Firmware v3.0.0 (released 29 August 2025) includes:

• ✅ Fix for USB passthrough stability

• ✅ Fix for EFR32 firmware update failures (Thread radio)

• ???? General improvements for SLZB-MR1U reliability

It is the recommended version for using external USB devices with MR1U.

???? Update options:

• OTA (if available), or

• Manual update via USB-C using the Web Flasher:
  ???? https://smlight.tech/flasher/#SLZB-06U-MRxU

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???? Setup Instructions

1. Flash your SLZB-MR1U with SLZB-OS v3.0.0

2. Plug the ZWA-2 dongle into the USB-A port

3. Open Z-Wave JS UI on your host system

4. Configure the serial port:

   
   

   tcp://<SLZB-MR1U-IP>:8638

5. Save settings and restart Z-Wave JS UI

6. Pair your Z-Wave devices as usual

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⚠️ Notes and Best Practices

• Only one USB device is supported at a time (multi-USB support is in development)

• Make sure port 8638 is accessible on your network

• Avoid running USB passthrough while flashing EFR32 (Thread) — even though the issue is resolved, it's a good practice to keep those tasks separate

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❓ Troubleshooting