Edison cann't connect pixhawk2

Hi,all

I installed the Edison module into pixhawk2, and flash apsyns-edison image to Edison, now I can run linux in Edison successfully, and I have set the parameters:
SERIAL2_PROTOCOL = 1
SERIAL2_BAUD = 921
LOG_BACKEND_TYPE = 3

but if I run command below:
spsync@apsync:~/dronekit-python/examples/vehicle_state$ python vehicle_state.py --connect ‘/dev/ttyMFD1,57600’

it print below:
Connecting to vehicle on: /dev/ttyMFD1,57600
link timeout, no heartbeat in last 5 seconds

I am not sure that baut rate, so I change the baut rate, and try another command below:
spsync@apsync:~/dronekit-python/examples/vehicle_state$ python vehicle_state.py --connect ‘/dev/ttyMFD1,921600’

unfortunity, the same error," timeout"

I am confused about it, woule you please give me some hints, thanks in advance…

Gavin

@rmackay9 Randy, do you have experience with this issue? Would really appreciate your help!

who can help me please!