Hi,
param show ARMING_CHECK does give a response to either, but then I connected mission planner and it suddenly showed:
Received 306 parameters
Saved 306 parameters to Drone450/logs/2017-09-07/flight3/mav.parm
After this, the command ‘param show ARMING_CHECK’ did work.
There is also a ‘param fetch’ command, but that doesn’t do anything. that seems like a bug.