shoat@cs.glasgow.ac.uk (Mr. David Shoat) (05/22/89)
What's the best (only?) way to break out from a DEC DELNI onto thin-wire? The DELNI, for the uninitiated, is a mains-powered device which emulates a piece of coax cable and some transceivers. You just plug up to eight transceiver cables from your systems into the box and it all works. There is also another port on the DELNI into which one is supposed to connect a standard thick- wire transceiver. This should let you break out on to a thick-wire network. Will this work with thin-wire, or do I need a repeater? Does anyone know why my whole damn network crashes every time I throw the switch on the DELNI which enables the external port? Thanks. David Shoat Dept. of Medical Cardiology Glasgow Royal Infirmary.
cyrus@pprg.unm.edu (Tait Cyrus) (05/23/89)
In article <2988@crete.cs.glasgow.ac.uk> shoat@cs.glasgow.ac.uk (Mr. David Shoat) writes: > >What's the best (only?) way to break out from a DEC DELNI onto thin-wire? >.... There is also another >port on the DELNI into which one is supposed to connect a standard thick- >wire transceiver. This should let you break out on to a thick-wire network. >Will this work with thin-wire, or do I need a repeater? No, you do not need a repeater. Yes it will work with thin-wire. I currently have a DELNI set up exactly that way. I have a DESTA (thin-wire transceiver) connected to this last port and I have not had any troubles with it. >Does anyone know why my whole damn network crashes every time I throw the >switch on the DELNI which enables the external port? Without knowing the topology of you network, I can't answer this. Are you sure you are not mixing heart beat with no-heart beat? > >Thanks. > >David Shoat --- W. Tait Cyrus (505) 277-0806 e-mail: cyrus@pprg.unm.edu University of New Mexico Dept. of Electrical and Computer Engineering Parallel Processing Research Group Albuquerque, New Mexico 87131
tedcrane@batcomputer.tn.cornell.edu (Ted Crane) (05/25/89)
In article <2988@crete.cs.glasgow.ac.uk> shoat@cs.glasgow.ac.uk (Mr. David Shoat) writes: > >What's the best (only?) way to break out from a DEC DELNI onto thin-wire? I just had occasion, today, to try this, and it worked: Connect a DESTA (< $300)) to the external Ethernet port on the DELNI. If you don't know which one that is, it is the one to which the DESTA fits without wierdness. There's only one. The slide switch has to be in the "external" position (open box as opposed to closed box icon). This connection is not documented anywhere that I found, and the local DEC folk wouldn't say that it's supposed to work. Common sense (along the lines of "Ethernet is foolproof, and if the cables match physically, they are meant to match electrically") says it should work ,and it does. >Does anyone know why my whole damn network crashes every time I throw the >switch on the DELNI which enables the external port? If you have no transceiver or transceiver-substitute (as in the above suggestion) connected to the port when its in external mode, you've got the equivalent of a plumbing system with an end cap left off. The bits spill out. Either disable the port (which still lets you chain DELNIs together) or connect a transceiver to it. Again, this should be intuitive!