I re post my question here hoping someone will lend me a hand.
I am running APM 2.73 with RDF900 with default radio setting. I can not send any command from flight data tab, eg : change altitude, change mode ect... Each time I try a error massage come out ( error change altitude...)
The strange things is I have another plane with completely same equipment and firmware, run with the same notebook but it was fine. I can do everything via GCS.
Please let me know where should I check or any setting to adjust. Thanks