DECrepeater 90C and DETRX-M?
Georg Schwarz
- DECrepeater 90C, presumably a 6 port BNC repeater made by DEC
- DETRX-M, to stack in the back of the repeater; has two TP ports
Does anybody know what those devices are exactly? What's that turn
switch on the DETRX-M for?
Unfortunately a power supply didn't come with that stuff. Does anybody
happen to know the required voltages or the pinouts?
Thanks.
--
Georg Schwarz http://home.pages.de/~schwarz/
ge...@epost.de +49 177 2437545
Alan Adams
ge...@epost.de (Georg Schwarz) wrote:
> I've obtained the following ethernet hub (?) from the year 1990:
>
> - DECrepeater 90C, presumably a 6 port BNC repeater made by DEC
> - DETRX-M, to stack in the back of the repeater; has two TP ports
6 front panel ports, 10base2, internally terminated, hence have to be the
end of the cable.
1 side BNC port not terminated.
Two rear serial ports for management interconnect between similar systems
(not data connection)
>
> Does anybody know what those devices are exactly? What's that turn
> switch on the DETRX-M for?
The switch selects the address used with the management information, so that
up to 16 units can be managed as a single hub.
> Unfortunately a power supply didn't come with that stuff. Does anybody
> happen to know the required voltages or the pinouts?
> Thanks.
5 volts for certain, maybe 12 volts, (but I don't think the 90C used 12v.)
Is the rating printed on the label which gets hidden when the units are
plugged together?
--
Alan Adams
alan....@orchard-way.freeserve.co.uk
http://www.nckc.org.uk/
Georg Schwarz
>Two rear serial ports for management interconnect between similar systems
>(not data connection)
that mean that the DETRX-M module does not provide any TP ethernet ports?
Peter LANGSTOEGER
>I've obtained the following ethernet hub (?) from the year 1990:
Depends on what YOU call a "hub".
DIGITAL/DEC used to call "hub" a backplane where you can plug in some modules
(like repeaters, bridges, terminal-servers, SNMP-Agents, Routers, TokenRing
MAUs, switches, ...)
DEChub90 and DEChub900 Series were/are the most popular Networking Components
sold by them (and then CABLETRON and now Digital Networks http://www.dnpg.com)
Other people/companies sometimes call a "hub" a multiport ethernet repeater
or even a multiport ethernet [cut-through or store-forward] switch.
I personally prefer the DEC nomenclature.
>- DECrepeater 90C, presumably a 6 port BNC repeater made by DEC
Yes. See http://digitalnetworks.net/dr/hubs/repeater/manuals/decmr-om.ps
>- DETRX-M, to stack in the back of the repeater; has two TP ports
http://www.dnpg.com/dr/npg/detfm-mn.html
Note: the 2 TP ports are for the management bus of the stack. They are
NOT 10BaseT. The (ThinWire) ethernet in the stack is connected by the
10Base2 Ports on the side of the modules via T-Connectors and of course
terminators on both ends of the stack/chain...
>Does anybody know what those devices are exactly?
Yes. But I'm afraid, you have only one part of a DEC Multi Stack Unit.
The grey plastic Carrier Part (for 19" rack mount) with the covered power
supply and the cable set (1 very short BNC cable, 1 very short UTP stack
management cable) seem to be missing.
> What's that turn
>switch on the DETRX-M for?
With this switch you specify the duty of this module in a complete stack.
One position (with the hat) is for the stack agent (eg. the DECagent 90
or another 90 series module with an integrated SNMP agent), another
position (with the bridge icon) is for the bridge (of course ;-) as a
stack is usually separated/connected from/to the real backbone with a
workgroup bridge (eg. the DECbridge 90) and the rest of the switch
positions are for the numbering of the other modules (so that the stack
agent can refer to them).
A DEChub90 (or DEChub900 for that case) is different.
The numbering is done via the slot position, the ethernet connection is
done via the rear connector(s) and the management bus is also done via
the rear connectors. You can connect two DEChub90 together with the BNC
connector on the right side of the hub. A single DEChub90 therefor requires
a (50 Ohm) terminator on this connector.
>Unfortunately a power supply didn't come with that stuff. Does anybody
>happen to know the required voltages or the pinouts?
Sorry, not yet.
I think the power supply is a H7082-AB, but I may be wrong.
--
Peter "EPLAN" LANGSTOEGER
Network and OpenVMS system specialist
E-mail pe...@langstoeger.at
A-1030 VIENNA AUSTRIA I'm looking for (a) Network _and_ VMS Job(s)
Hans Vlems
backplanes.
That's where the swicth comes in.
Only the Bridge90 and Agent90 modules use 12 V (provided on the 8 slot hub
90
on slots 7 and 8 only).
Perhaps www.dnpg.com still has some documentation for these components.
Georg Schwarz <ge...@epost.de> wrote in message
news:aaa1d1$d7q$1...@mamenchi.zrz.TU-Berlin.DE...
Peter LANGSTOEGER
>Only the Bridge90 and Agent90 modules use 12 V (provided on the 8 slot hub90
>on slots 7 and 8 only).
Nope. All modules with AUI (or RS232) ports (eg. the DECrepeater 90FA) use
12V (and therefore slot 7-8 in DEChub90).
But the original post is about the DEC MultiStack and not the DEChub90 itself.