Always run the 1tool_prerequisites_setup.exe and 1tool_setup.exe as an Administrator on Windows.
If you are an HVAC technician or automation engineer working with , encountering a "download failure" or a bug in the 1tool environment can halt your entire project.
Carel uses a proprietary TTL (5V) or RS232 programming interface, depending on the controller model. Standard null-modem cables may not work.
: During the setup wizard, ensure you explicitly select both 1tool and USB Driver . Failure to install the driver during the initial download phase will prevent the software from recognizing your hardware later.