As Spiker said, the #5 position should be 28" but don't count on it. The only way to know for sure is to physically measure the draw length. Many bows, Martin included draw longer than their module setting specifies. It's not all that important that it be right on the money. The reason to measure it is so that you know what it really is. Once you have the bow set where you like it it makes sense to measure it so that if you make other adjustments or change string/cables in the future you can set it for the same length. Another thing I'd advise is taking a pencil and drawing a line on the left/drawstop side of the cam where it passes through the limb fork, front and back side of the limb. Having this gives you a visible reference to cam orientation in the event that the string/cables creep and you can adjust back to the original setting. It also helps for setting the draw length again if you change the rigging.
If You're Not Living on the Edge You're Taking Up Too Much Space
Martin/Rytera Staff Shooter
PSAA Life member, UBP Life member
PADI AOW Diver