Serial Communication Problem with ADM3251

Hello there,

My ADM3251 Is sending random values. I am using EVAL-ADM3251EEBZ for testing the ADM3251 for RS232 communication. I am using particle electron for sending data and at the other hand I am using serial monitor for monitoring the communication via USB to TTL converter. I am giving 5V as a input and also separate 5V to Viso. When I directly read the data from particle it is giving me correct data  however when I send it through eval board it is not getting detected or reading the  true value. Can you guide me through the process?