The GM338 uses a specific cable that plugs into the mic jack on the front of the radio (usually an RJ45 to USB or RS232 adapter).
This usually means your software version is older than the firmware currently on the radio. You must upgrade to a newer CPS version. If you'd like to move forward, tell me: operating system are you using (Windows 10, 11, etc.)? Do you already have the programming cable Are you looking to program frequencies or specialized (like MDC1200)? motorola gm338 programming software download upd upd