You have the option of using the hinge system provided by the automation contractor, or choosing to go with the below style adjustable hinge system proivided by CPW.  The below sleeve hinge is to be welded directly to your installed 6x6 steel posts at a height called out in the CPW drawings. This hinge “sleeve” will arrive at the job site at a prescribed length prior to the gate’s arrival to facilitate the coordination and completion of pillar construction. Often times the steel posts will be clad with concrete block and surfaced with stucco, stone or veneer to fashion a masonry column. It is best to embed the CPW hinge system directly to the core steel post prior to the masonry. If the steel posts are to be wrapped by a CPW Gate Column, the same application occurs but with a CPW-supplied hinge that extends 2-1/16" longer for Gate Column installation.

To set the height of the hinge to the steel post, use a transit. The hinge sleeve can be cut to length on-site so it is flush with the masonry. For gates without embedded steel frames, the opposite plate mounts to the edge of the gate with a provided 1/4" lag bolt. For gates with embedded steel frames, the opposite plate arrives already welded to the embedded steel frame through a mortised section on the edge of the gate.

The following images should help.
A:  Plan View diagram
B:  Hinge image
C:  Hinge detail diagram
D:  Plate images for embedded steel gates
E :  On-site application images

A:  Plan View Diagram

Often, to protect against installation blemishes, the gates are
mounted while still shrink-wrapped, as shown. 

Her, showing the sleeve (on the left) exposed through a masonry column.  The plate on the right
is welded to the gate steel frame, and in this application, the plate is offset, alowing the Drive Gate to clear a protruding base of the column when open.