Mitsubishi Heavy x-y line protocol

I am trying to understand Mitsubishi Heavy Air conditioner protocol. Its really interesting and different from other protocols than i have seen before.
Here i put some package examples
0xFB 0xFE 0xFE 0x7F 0xFE 0xFE 0xEF 0xFD 0xFB 0xFB 0xFE 0xFB 0xFE 0x7F 0xFE 0x7F 0x7F 0xF7 0xFE 0xFE 0xFE 0xFE 0xFE 0xFE 0xFE 0xFE 0xFD 0xFE 0xFE 0xFE 0xFE 0xFE 0xFE 0xFE 0xFE 0xFB 0x7F 0x7F 0xF7 0x7F 0x7F 0xF7 0x7F 0x7F 0xF7 0xF7 0xFD 0xFE vane 1
0xFB 0xFE 0xFE 0x7F 0xFE 0xFE 0xBF 0xFD 0xFB 0xFB 0xFE 0xFB 0xFE 0x7F 0xFE 0x7F 0x7F 0xF7 0xFE 0xFE 0xFE 0xFE 0xFE 0xFE 0xFE 0xFE 0xFD 0xFE 0xFE 0xFE 0xFE 0xFE 0xFE 0xFE 0xFE 0xFB 0x7F 0x7F 0xF7 0x7F 0x7F 0xF7 0x7F 0x7F 0xF7 0xDF 0xFD 0xFE
0xFB 0xFE 0xFE 0x7F 0xFE 0xFE 0xEF 0xFD 0xFB 0xFB 0xFB 0xFB 0xFE 0x7F 0xFE 0x7F 0x7F 0xF7 0xFE 0xFE 0xFE 0xFE 0xFE 0xFE 0xFE 0xFE 0xFD 0xFE 0xFE 0xFE 0xFE 0xFE 0xFE 0xFE 0xFE 0xFB 0x7F 0x7F 0xF7 0x7F 0x7F 0xF7 0x7F 0x7F 0xF7 0xF7 0xF7 0xFE

0xFB 0xFE 0xFE 0x7F 0xFE 0xFE 0xEF 0xFD 0xFB 0xFB 0xEF 0xFB 0xFE 0x7F 0xFE 0x7F 0x7F 0xF7 0xFE 0xFE 0xFE 0xFE 0xFE 0xFE 0xFE 0xFE 0xFD 0xFE 0xFE 0xFE 0xFE 0xFE 0xFE 0xFE 0xFE 0xFB 0x7F 0x7F 0xF7 0x7F 0x7F 0xF7 0x7F 0x7F 0xF7 0xF7 0xDF 0xFE
0xFB 0xFE 0xFE 0x7F 0xFE 0xFE 0xEF 0xFD 0xFB 0xFB 0xBF 0xFB 0xFE 0x7F 0xFE 0x7F 0x7F 0xF7 0xFE 0xFE 0xFE 0xFE 0xFE 0xFE 0xFE 0xFE 0xFD 0xFE 0xFE 0xFE 0xFE 0xFE 0xFE 0xFE 0xFE 0xFB 0x7F 0x7F 0xF7 0x7F 0x7F 0xF7 0x7F 0x7F 0xF7 0xF7 0x7F 0xFE

Bytes only has one ‘0’ this shows the value of the byte
I think 3 bytes means only one value.

I have tested and i am sure these values are right.
0xfe means ‘0’ because ‘0’ is at the start of the byte.
the byte at the right is high byte and the left one is low byte.
every shifting to left on high byte increases the value +4
every shifting on low byte increases value +0,5
0xBF 0xEF setpoint 19 10111111 11101111
0xFE 0xDF setpoint 20 11111110 11011111
0xFB 0xDF setpoint 21 11111011 11011111
0xEF 0xDF setpoint 22 11101111 11011111
0xBF 0xDF setpoint 23 10111111 11011111
0xFE 0xBF setpoint 24 11111110 10111111
0xFB 0xBF setpoint 25 11111011 10111111
0xEF 0xBF setpoint 26 11101111 10111111
0xBF 0xBF setpoint 27 10111111 10111111
0xFE 0x7F setpoint 28 11111110 01111111
0xFB 0x7F setpoint 29 11111011 01111111
0xEF 0x7F setpoint 30 11101111 01111111

What i am trying to do is checksum calculation.
The last three bytes are changing if other bytes changes. I think the checksum is those bytes.
Do you have any idea how is calculated the checksum?
And this protocol is a common protocol?If yes what is the name of it?