I've been looking high and low to find an answer to this question and none of the answers I have found online seem to work. I am at wits end and really need to find an answer to this question. I am using a MacBook Pro running El Captian OS X. I have TrendNet TU-S9 USB to Serial converter with the latest driver. I am using the "screen" command with Mac terminal. I am unable to send a control break to a router or switch to get into ROMMON.
Everything online tells me that I just need to hit Ctrl-A Ctrl-B or any number of variations that should accomplish this. Nothing seems to work. I am hoping that there is someone else out there who is using a similar set up and has been successful getting into ROMMON from a MAC.