Creating Damage Shields through Enchanting question

Caroloces

I notice the Essence rune, Deteri, creates a damage shield for a certain span of time if you use it as an additive property on weapons. I'm curious as to how the damage shield is activated or "procced". I have a damage shield that's activated on my armor set, but that's dependent on my level of health sinking below 30% (I think).
So if you enchant a sword, for example, with Deteri, Jejora potency, and Ta Aspect Runes, you get a Slight Glyph of Hardening (Grants a 130 point Damage Shield for 5 seconds). What do you do with the sword to activate the damage shield? And, the obvious question that goes along with that is, how frequently can it be activated (What is the cooldown?)

CP5

When you attack with the weapon or weapon skill (may be a few others like caltrops) it will proc if its off cooldown. The cooldown, iirc is 4 seconds? Someone may want to correct me on that if its changed or off.

Athas24

ya its based on the hit and if the CD is up or down. That's about it. when you do a white hit with it you should see the shield visual proc, I'd imagine.

Nestor

I looked at the Damage Shield enchants and decided that the Glyphs that increase over resistance and armor would serve me better. No Cool Downs, no Procs. Have not looked in detail since 1.6 came out, but I don't think that the Damage Shield that processes on a hit is all that much more powerful than one reduces Physical or Spell Harm.

The other thing to consider, the Damage Shield one can only be used on Weapons, so you get one of those. Where you can use Glyphs that reduce Physical or Spell Harm on each of the 3 jewelery pieces. So, how you combo these may have some influence on what choices you make.