Mission Planner won't make Command Mode connection with SiK radio (RFD900x)

I’ve dusted off my RFD900x radios for a project.

They work great, and I’ve set them up with the RFDesigns Config program and a FDTI cable.

For some reason, Mission Planner can’t enter command mode with these radios.

I know the radios are working fine with command mode because I can get to them with the RFDesigns config program. I’ve used that program to update the settings on both my air and ground RFD900.

I updated to the latest beta of Mission Planner just to make sure this hadn’t already been fixed.

Even though I can’t get Mission Planner to enter command mode with these radios, they do connect fine and transmit telemetry. I just can’t use Mission Planner to change the radio settings.

Thanks!

Disconnect the radio from the FC, the command to switch to command mode can be suppressed by the mavlink comm from the FC.

I want Mission Planner to be able to change RFD900’s settings - and that requires them going into command mode.

For anyone not familiar with this - the command mode is identical to how we used to do it on telephone modems using the Hayes “AT” command set.

As I recall, sending three plus signs (“+++”) when in data mode will switch the modem over to command mode. Changes to the modem settings can then be entered with commands that begin with “AT”.

The command set on the RFF900 radios also have an “AT” command to make changes to the modem on the other side of the connection. (I think it’s “ATZ” - but I don’t remember for sure.)

Anyway, for normal operation, we need this Mission Planner function to work.

Is your air radio connected to the FC (which is on) when you tried to enter command mode on the ground radio ?

Let me explain in greater detail.

My copter is fully powered up. The flight controller has a usb connection to my PC running Mission Planner.

When I go to Mission Planner’s SiK radio section I choose “load parameters” - and that fails. The error message says it can’t enter Command Mode.

In normal operation, I can use the SiK radios (RFD900x’s) to connect between the copter and the PC running Mission Planner. The radios are working fine for telemetry.

I’ve also verified both my radios are working by connecting each to a FDTI cable and using the RFDesign config utility. This utility works fine to configure both my radios.

BTW - there’s a fairly new version of the RFDesign config utility - it came out in April 20204.

So there just seems to be a problem with Mission Planner’s ability to configure SiK radios - and the error message says it can’t enter command mode.

OK - I figured out my problem - and I’m feeling a bit stupid about my mistake.

As I was using Mission Planner connected to my aircraft via a USB cable, I mistakenly thought that the “near side” SiK radio was the one on the aircraft. Nope.

Thanks for your (and anyone else reading) patience.