Arrival Jam describes how default zone to zone logic utilizes the Jam Time value for the discharging zone to wait for the accepting zone to indicate successful arrival of the carton into the accepting zone. In certain applications for a given zone, you may want to disable this functionality

Clicking the Disable Arrival Timeout check box will prevent the discharging zone from registering an Arrival Jam condition. Upstream cartons will not wait to enter the discharging zone once a carton has left the discharging zone