Sending multiple uint16 numbers serially from one LaunchXL F28379D to another Launchxl F28379D

I am trying to send 15 uint16 numbers serially. I use the built-in Simulink blocks for Launchxl SCI Transmit and SCI Receive. When I transmit 3 uint16 numbers it does not give any error but when I increase numbers from 3 to 15 the SCI Receive Block gives 1 in Status Output which means: 1 — A time-out occurred while the block was waiting to receive data.

My setup: I deployed Simulink program to one LaunchXL which transmit data regularly with time step 0.01. Then connect it to another Launchxl using Tx Rx pins. Then I read the second LaunchXL in Simulink External Mode with Time Step 0.01. Then I get this error message from Receive Block.

What could be the problem? Or possible solution?