The IC-7100 can use the USB-RTS01 from RT Systems or the RT-41 (USB-A to USB mini-B) cables for programming and control. This comparison will help you decide between the two cables.

USB-RTS01 The USB-RTS01 cable works through the CI-V port on the back of the radio. CAT commands for radio control and programming commands are passed through this port.

This cable is based on an FTDI chipset and uses the RT Systems USB drivers. It works well with other applications (control, logging, and others that work through the CAT commands). It is a good choice to help avoid a driver conflict with other devices connected to the same computer.

This cable is comparable to the Icom CT-17 cabling with only one connection. Although it carries a 3.5mm stereo plug at the radio end, that plug is wired as mono as needed by the connection of the radio.

RT-41 The RT-41 is a USB-A to USB mini-B cable that connects to the USB connector that is between the External speaker jack and the CI-V remote jack on the back of the radio. Drivers from Silicon Labs associated with the USB electronics built into the radio will be loaded when this cable is used.

Realize that many devices use the Silicon Labs drivers. In the radio world, Kenwood, Icom and Yaesu all use these drivers. This can result in conflicts between devices if you have several things connected to your computer at the same time.

As long as no conflict exists, this cable has the advantage that 1) one like it comes in the box with the radio when the radio is purchased new. 2) On some radios, more advanced commands are handled through the USB port. So you will get more from your radio through this cable connection. 3) This is an older style Android cable. You may have one available if you don't have the one from the original packaging. Cameras and phones used this cable several years ago. If the one you have is wired correctly, it will work. It should be worth the try if the plug fits the radio.