XBee 900HP MY 0 command


I am having issues sending the ATMY 0 command, default UART settings. I keep getting errors and I am unsure why. I am trying to do point to multi-point communication as demonstrated here. https://www.digi.com/resources/documentation/Digidocs/90002173/#reference/r_point_to_multipoint.htm%3FTocPath%3DNetwork%2520configurations|Network%2520topologies|_____2

Below is a link to an image of my digital serializer data. I only have Power, Data In, Data Out,Pins 4,9,10 and 11 are all set to ground. Reset pin is sitting at 2.4V.

Data: https://postimg.cc/5j5xQf2f