In Memberium’s advanced settings under “Login Handling” The “Maximum Login Window (Hours)” is the number of hours that a user can be logged in from using different IP addresses. You can control the number of IPs a user can be log in with during that time by setting the “Maximum Login IPs” just below it.
For example if you set it to three IP addresses in 24 hours, then when you went to login from a fourth IP address you would be denied until the timer ran out.