Do cyclone IV FPGAs support dynamic reconfiguration?

there is a configuration mode in fpga that lets you to be configurred by another fpga. here where i work they use max 3 or any other fpga. at any moment,max 3 will recieve new config data from LAN lets say, and will shut down the fpga. it will then automatically reconfigure it and fire it up on new wheels. but its not possible to reconfigure the fpga without shutting it down (i think). simply because many "config signals" requere fpga to be in shut down mode. - it is a half working condition when fpga is shot down but partially operational to recieve new config data. ...i think you could buffer any working information in DDR, then reconfigure the fpga and download the data back.