Currently, the send udp command in BrightAuthor doesn't include a carriage return. But, firmware does support it. You can send a udp command with a carriage return using a plugin.
The following plugin, https://www.brightsignnetwork.com/download/Scripts/UDP-CR-Command.zip, allows you to send a udp command with a carriage return attached. You just have to add the plugin to your brightauthor project, choose send plugin command from advanced commands-send, and then use the following syntax:
THe name of the plugin is "udpcr". You include the name when you add the plugin under file, presentation properties, autorun.