Removing the mask of the serial communication

Hi! I'm currently using Matlab to transmist my serial data to my modem. I'm using portmon to monitor the packets that I am sending to the modem. Everytime I send a data, the data is being masked saying this:

SUCCESS Mask: TXEMPTY CTS DSR RLSD BRK ERR RING

Is there a way to remove the mask? I read in other forums that the reason why my modem can't receive the data properly is because of the mask