Problems with RTDE Receive

I have tried the io_example in C++ and Pyhton in Ubuntu with a UR5 robot and they don't well because when second rtde_receive_.getDigitalOutState(7) is executed and this digital out change from 0 to 1 , the return isn't 1 and the programs have a delay greater than 8 ms (125 Hz) can you help me? Thanks