Relay logic simulation

Hi all,

We've been asked to design a number of control / protection schemes lately which are increasing in complexity. Can anyone point us towards a simple software tool to model the relay logic we can use to sense-check the design (after a manual check of course) and highlight any faux pas before things get built? Really just to look at checking relays in series/parallel etc are doing the right thing, not a full-on circuit emulation, i.e., with these inputs changing to this state, we get these outputs live with that happening after the programmed delay and so on.

In an ideal world it would be able to read a design straight out of our CAD (ACE), but I suspect that's too much to ask!