Looking at Matlab (Simulink) com3 configuration :

Communication Port :COM3
Baud Rate : 115200
Data Bits: 8
Parity:none
Stop Bits:1
Byte Order: LittleEndian
Flow Control:none
Time Out:10


Now as i mentioned above Com3 and Com5 are virtually paired by the software
com3 is receiving the same data as com5
com3 receiving configuration in simulink are:
Communication Port: COM3
Header:none
Terminator:none
Data size:[4 1] it means an array of 4 * 1 matrix
Data Type:Single