SLZB-xxU and ZWA-2

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

Overview

Many users have asked whether the ZWA-2 Z-Wave USB stick can be used with the SLZB-MR1U through its USB passthrough feature.

Until now, we were unable to confirm compatibility — as we had not yet tested this specific configuration.

We have now tested the setup with the latest firmware, and we are happy to report that:

✅ ZWA-2 works perfectly with SLZB-MR1U over Ethernet using USB passthrough.

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✅ What You Need

• SLZB-MR1U (hardware)

• SLZB-OS v3.0.0 firmware

• ZWA-2 Z-Wave USB stick

• Z-Wave JS UI or other Z-Wave software that supports TCP/IP serial passthrough

• Network access to SLZB-MR1U IP address

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

We recommend using SLZB-OS v3.0.0 (released 29 August 2025) because:

• It resolves previous issues with USB passthrough stability

• It fixes EFR32 firmware flashing problems (Thread radio)

• It’s the first firmware version to officially support stable external USB devices like ZWA-2 on MR1U

???? Download SLZB-OS v3.0.0
Update via web flasher (USB-C) or OTA if available.

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????️ Setup Instructions

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

2. Plug the ZWA-2 USB stick directly into the USB-A port of the MR1U

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

4. Configure the serial port as:

5. Save settings and restart Z-Wave JS UI

6. You should now be able to include/pair Z-Wave devices as normal

???? Example configuration screenshot:

(Insert image here of Z-Wave JS UI settings and USB stick connected to MR1U)

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???? Notes and Best Practices

• USB passthrough works best with powered USB hubs if you plan to add multiple USB devices (coming soon in future firmware).

• Only one USB device is supported at the moment.

• Ensure your network firewall allows access to port 8638.

• Avoid using USB passthrough and flashing EFR32 at the same time — even though the issue is resolved, it's best practice to do these separately.

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❓ Troubleshooting