RDNet 4.0.7463.4164 was available to download from the developer's website when we last checked. We cannot confirm if there is a free download of this software available. The most popular versions of the tool 3.1, 2.2 and 2.0. This free software is an intellectual property of RCFGroup.
The latest version of the software is supported on PCs running Windows XP/Vista/7/8/10/11, 32-bit. RDNet lies within System Utilities, more precisely Device Assistants. RDNet.exe is the common file name to indicate this program's installer. We recommend checking the downloaded files with any free antivirus.
From the developer:
RDNET is a proprietary protocol of a network that allows for connecting up to 256 compatible audio devices (i.e. professional RCF loudspeakers mod. TTL55-A, TTL33-A, TTL31-A, etc.) to a computer (PC with Microsoft Windows® o. s.) to check and remote control them.
You may want to check out more software, such as DVA Network, which might be similar to RDNet.