Do i understand that right and you do all those 7 exercises on 4 days a week ??
with 3x12 per exercise that is 36 reps per exercise, and 36 *7 = 252 reps per day, and 252*4 = 1008 reps per week. with this being ( 3*7*4) 84 sets per week ..
I'd defenitally call that done too much for the abs only.
Do you even have time for other exercises ? alone repping those down probably takes a minimum of 30 minutes each day. (including the times to go from one machine to the other and to the hanging bar and incline bench etc)
My next question would also be: what other exercises do you do ?
If your back related pulling exercises (rom. deadlifts, bend over rows, back extentions etc) are not at least the same amount, you also might run into postural issues very soon. (hence your abs will become shortened and tight due to the bigger muscle structure, and will begin to pull your upper body forwards and down)
A good rule of thumb is normally 20-25 sets per week for the bigger musclegroups.
I'd rather do abs on 2 days and give it your all, instead of grinding them down that much. Especially since they are also involved in every compound move and every standing exercise etc. you're just killing them if you do that amount of work to them.
You could also do every day 1 exercise so you get to the right amount of sets per week, but it's not as effective as training them more intense on 1 ore two days with several exercises being done.
And as already said, i hope your pulling work is 'on par'. Normally the back pulling should always be a tad more than the pressing or crunching forwards.
And it is never a good thing to drind down the same type of exercise that often. Because it also can lead to overuse issues.
so far my 2 cents :)
Cheers!