Different amount of MAVLink messages received

Hi,

The flight controller I got is Pixhawk px4 bl fmu v2.x.

I also have a imx6 board (linux kernel ubuntu system) to receive the MAVLink messages from the controller. I do a serial programming in C to get the data from the serial port (ttyACM0) which connected to the flight controller. However, I could only receive the messages with ID 0, 30, 178 and 74. I checked the sequence number and it shows no packets loss. Actually, I need more data from the controller.

Then, I connect the controller to my PC (windows 7 system) and use the QGroundControl. By this, from the MAVLInk inspection, I can see that it receives much more messages with different kinds of IDs (more than 15 or 20). That’s what I want. I am new to the flight controller and the MAVLink. I get confused. Why it has such much difference between them? What is the possible solutions? and how can I get same amount of IDs on the imx6 board (linux)?

Thanks in advance!