Conference 7.286::fddi

1028.0. "copper fddi problem" by SNOFS2::TAYLORGRAEME (speedie) Thu Jul 15 1993 04:07

    	Have a customer with a vaxstation 4000/90 connected to a
    deconcentrator 500 with 81 metres of thin wire cable. The fddi
    interface in the the 4000/90 is defza-ca (copper version). Every few
    days the link to the deconcentrator has an ajacency, which causes a
    major problem as this box is running decmcc with all it's rules going
    mad as it sees many nodes disappear. Have replaced the defza,
    turbochanel board and the system board in the 4000/90, the 6 port
    concentrator card and the thinwire cable. Have managed to reduce the
    problem with the current thinwire cable which replaced one that was 86
    metres long. Have also run an earth cable from the 4000/90 to the
    concentrator, but it still occurrs. Before the earth cable was
    installed the voltage between the thinwire cable ground and the chassis at
    either the 4000/90 or the deconcentrator 500 with the cable disconnected 
    was 0.06 volts. Any ideas out there??
    
    
    thanks in advance