Does Cox Limit the Number of Devices to Private Home Wi-Fi Router?

We have a cable modem and router (separate units) that we have supplied ourselves (that is, they are not ones we rent from Cox). 

Does Cox limit the number of devices (e.g. laptop, Macbook Pro, iPhones, iPads, Roku boxes, etc.) that I can connect to the internet through my router? I heard someone mention once that they had an issue with the number of devices that their ISP allowed them to connect to their Wi-Fi router, but I wasn't sure if that was something that Cox did or not.