My John's in an EMI unit too.
I must admit I wasn't happy about it initially, but in fact the care he is receiving is wonderful.
There are keypads on the doors into the main section of the home, and more keypads between the two EMI sections.
There's a higher staffing ratio than in the main units, and there's always a trained nurse on duty. The two charge nurses are RMN.
The carers all receive training for NVQs, (SVQ here), levels 1 - 3, and any that aren't dedicated don't last long! It's a hard job they do, for very little pay, and I think they're wonderful.