Display of Pulse Counts on LCD (16 X 2) using LINX and LAbview

Hi,
I m beginner to Arduino. I want to count the number of pulses in specific time(sec/ms) by using in-board frequency generator/Oscillator of Mega 2560.

I am using Lab view 2014,LINX,LIFA. After completion of uploading the firmware by using LINX, but got problem at Tx of 2560 which is not blinking,(Rx is working fine) this issue is arising during execution of VI file.I dont know where is problem.