I have a random question that I have never been able to get a clear answer on.  Is there anyway of creating an AB Line with a pro700 + 372 RTK receiver on a side by side?

So what I am shooting to do is simply go out create a 1' implement and create straight AB lines along fence lines, field edges, etc. I am going to have the receiver mounted perfectly to be the correct distance away from any obstructions (power poles, fences) so the planter, sprayer, etc all clear without issue. These AB lines then I would be able to simply pull in with the planter remark it over 30' (24 row planter) and be good to go. 

Before anytime I mounted the receiver and pro700 all that I can do is record boundaries and there was no option for ab line creation. Didn't know if I was missing something or what.