For several boxes in internal network
1 ) all boxes should have different IP eg
192.0.168.10 , 192.0.168.30 , 192.0.168.30 and 192.0.168.40.
2) all boxes should be forwarded to different ports eg 192.0.168.10 port 12000 ,192.0.168.20 port 12010 , 192.0.168.30 port 12020 and 192.0.168.10 port 12030
3 ) maby the server will read the card better on external serial cardreader + newCS .