How to use FEC block in GRC?

Hi, I’m making a program which I attached to the mail.How can I put fec
block (ex. En/Decode CCSDS 27, Viterbi Combo) to theseblock diagrams?

#Sendervlc -> udp source -> ofdm modulation -> usrp
#Receiverusrp -> ofdm demod -> udp sink -> vlc

Speck of SW and HW are below.
#GNU Radio: ver 3.7.0UHD$B!’(Bver 003.005.003USRP$B!’(BN200Daughter
Board$B!’(BXCVR2450 2.4GHz-5.0GHz
##SenderCPU(Host): XeonVirtual Box$B!’(Bubuntu12.04LTSMemory: 25GByte
##RecieverCPU(Host): XeonVirtual Box$B!’(Bubuntu12.04LTSMemory: 25GByte
Sender and Reciever are connected to the same PC.
#OthersDistance between antenna: 1[cm]
Thanks.
Mitsu