T-taps are allowed on Simplex addressable systems. I'm not sure if there is a maximum number of T-taps per Mapnet zone. If you remove a head or a base you do get notification of that trouble. T-tapping is a nice feature for the troubleshooter because when you have to remove a base for replacement you don't end up with up to 256 missing heads. These are initiating circuits and NOT signal circuits. I've had lots of experience on 4100, 4100U panels and on hardwired in lots of buildings, installation and repair.
Dave
