[Info-vax] terminal servers etc

[Peter 'EPLAN' LANGSTOeGER]

In article <kccmc4$5j7$1 at online.de>, helbig at astro.multiCLOTHESvax.de (Phillip Helbig---undress to reply) writes:
>OK, if it is in the hub, everything works through the hub, meaning the 
>BNC connection on the hub goes to the outside world.

For the module in the hub, yes. The hub is the world.
(a repeater module with a fibre link could see this differently ;-)

For the hub, no.
Usually the outside world was behind a DECbridge (in slot 8)

The BNC connector on the side of a DEChub90 was intended to
link 2 DEChub90 together (to have one uplink slot, one agent
slot and 14 module slots - gaining 2 slots over 2 single hubs)
For this, there was the MMJ port on the right side (to connect the
management of one DEChub90 to the DECagent90 in the other DEChub90)

>If not, then the 
>BNC (terminate if not used) and UTP connectors to the outside world 
>work.

If you don't use the module in a DEchub90, then it is good practice
to terminate the BNC interface (with a T-connector and 2 terminators)
if unused (in standalone configuration) - but what for with a DECserver?

But if you use the UTP on the front, the BNC doesn't need a terminator.

>I see that the DECserver (but not the DECrepeater) also has a power 
>connection on the back, so can be run outside the hub.  The repeaters 
>presumably don't need power, or get what they need through the 
>backplane.

I don't remember having seen a module without the power connection on
the back (but can't swear on that) but without it, you can't use the
module as really standalone then (only in a DECstack90 ;-). Repeaters
also do need power and yes, the DEChub90 connector is for net & power.

>On another server and repeater (not in the hub and no connector for it), 
>there is the same power connector, but an additional circular switch.  
>What is the latter for?

I do remember circular switches only on the "backplane" piece of a stack
http://www.servershop24.de/images/produkte/i10/100560-decbridge-1277821213-1743.jpg
So, maybe you have this part of the DECagent90 still on the DEC90 module
and need to take it off (and reseat it in the rest of the DECstack90 ;-)

-- 
Peter "EPLAN" LANGSTÖGER
Network and OpenVMS system specialist
E-mail  Peter at LANGSTOeGER.at
A-1030 VIENNA  AUSTRIA              I'm not a pessimist, I'm a realist