ACCON-S7-NET 3.5.0.3 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. We recommend checking the downloaded files with any free antivirus.
You can set up ACCON-S7-NET on Windows XP/Vista/7/8/10/11 32-bit. This free software is an intellectual property of DELTALOGIC Automatisierungstechnik GmbH. The program is included in Internet & Network Tools. The most popular versions among the program users are 3.5, 3.3 and 3.2.
From the developer:
ACCON-S7-NET is a program that allows you to configure the S7 PLCs from Siemens. Most of the devices support communication via TCP/IP. The program can be used for remote maintenance via your router, Intranet and Internet. The device can be connected to the PC via a hub or switch.
You may want to check out more software, such as COMODO Firewall Pro, SecureCRT or NetCafe, which might be related to ACCON-S7-NET.