The SR2 USB01 is a programming cable for Schneider Electric’s Zelio Logic smart relays (SR2 series). By 2021, Microsoft had already released several major updates to Windows 10 (versions 20H2, 21H1). Schneider Electric did not provide a standalone signed driver for the SR2 USB01 in 2021. Instead, the driver was bundled within the Zelio Soft 2 software (version 5.4 or later). Users in 2021 reported success using the driver included with Zelio Soft 2, though installation required manual steps due to the lack of a modern Windows Hardware Quality Labs (WHQL) signature for the USB-to-serial bridge chip (often a Prolific PL-2303 clone or older variant).
The safest and most reliable method to obtain the driver is directly from the Schneider Electric website. Avoid third-party "driver updater" tools, as these can bundle malware or install incompatible software.
Here is a 60-second checklist to ensure success: zelio sr2 usb01 driver windows 10 download 2021
Some SR2 USB01 cables manufactured before 2016 contain chips that are intentionally blocked by modern drivers. If the official Schneider driver fails (still shows Code 10 or Code 43), use this emergency 2021 workaround:
Warning: Use this method only if the official driver fails. It uses a vintage driver (3.3.2.105) known to work with older Prolific chips. The SR2 USB01 is a programming cable for
Important: This driver is unsupported and may cause BSODs. Use it only for programming, then unplug the cable.
After installing either Zelio Soft 2 or the CP210x driver: Some SR2 USB01 cables manufactured before 2016 contain
As of 2021, official downloads were only available via Schneider Electric’s website:
| Item | Source | Notes | |------------------------|------------------------------------------------|----------------------------------------------| | Zelio Soft 2 (full) | Schneider Electric SE Download Center | Includes SR2 USB01 driver. Free to download. | | Standalone SR2 USB01 driver | Not officially provided by Schneider | Unsupported; manual extraction required. |
File examples (2021 timeframe):