Can I have more than one doorbell on the same doorbell push button?

Absolutely. ActivLink makes it easy to link Honeywell Doorbells with a Honeywell Door Push, so you can place doorbells in different locations throughout your property. Be sure to select a doorbell with the number of inputs you need, using the guide below as reference:
Series 3 (RDWL311A) -- 2 inputs
Series 3 (RDWL313A) -- 4 inputs
Series 5 (RDWL515A) -- 4 inputs
Series 9 (RDWL917A) -- 6 inputs