| T.R | Title | User | Personal
Name | Date | Lines |
|---|
| 3766.1 | | USPS::FPRUSS | Frank Pruss, 202-232-7347 | Mon Aug 05 1996 17:52 | 7 |
| 1) Was the DESTA working earlier? I've had several die on me.
2) What was this DEUNA last connected to?
3) The DESTA has a set of switches to turn heartbeat on/off, DEUNA
needs HB, I believe.
4) If the DESTA is just terminated with a T, will the DEUNA init?
|
| 3766.2 | What is the Thinwire length? | KEIKI::WHITE | MIN(2�,FWIW) | Tue Aug 06 1996 00:21 | 5 |
|
Using the BNC on the side of the DECHUB90 limits the thinwire
length to approx 90 meters.
Bill
|
| 3766.3 | Has the customer tried this? | USPS::FPRUSS | Frank Pruss, 202-232-7347 | Tue Aug 06 1996 02:06 | 5 |
| And why do you say that not using a T and Terminator at the DEChub 90's
BNC "is correct"? It does not seem reasonable to me that this is
correct.
FJP
|
| 3766.4 | Quickee thinwire rules... | NETCAD::BATTERSBY | | Tue Aug 06 1996 10:15 | 21 |
| >And why do you say that not using a T and Terminator at the DEChub 90's
>BNC "is correct"? It does not seem reasonable to me that this is
>correct.
Hi Frank. The DEChub 90 thinwire segment on the backplane provides
50 ohm impedance termination, and as such the external cable connected
to the side BNC of the DEChub 90 backplane does not require a T and
terminator. The other end of the thinwire cable connected to the
side BNC of the DEChub 90 backplane is required to have a T and
50 ohm terminator.
RE: (base note) - As has already been mentioned the thinwire segment
on the DEChub 90 backplane is equivalent of 65 meters of thinwire
cable out of the maximum allowance of 185 meters of a thinwire segment.
The backplane must be at one end of the thinwire segment used to
connect to other external devices.
For cable length planning, this means that only 120 meters of thinwire
cable can be used to connect other devices.
Also, a DEChub 90 backplane is the equivalent of 15 nodes on a
thinwire segment.
Bob
|
| 3766.5 | I'll take your word for it! | USPS::FPRUSS | Frank Pruss, 202-232-7347 | Wed Aug 07 1996 17:59 | 13 |
| The Network Products guide discusses hooking two DEChub 90's together
using the BNC port.
Does this mean that:
1) In this case you would use no T&T at all?
2) Could anything else be on the TW segment between the two hubs?
3) I guess you can only put two hubs on this segment, then...
Frank
|
| 3766.6 | Count the Hub90 backplane's distance and taps. | JULIET::yosmte::HARRIS_MA | Sales Executive II | Wed Aug 07 1996 18:27 | 10 |
| RE: -.1
The Hub90 itself counts for 65meters (I think) of cable and 12 or so
Ethernet taps on the 'thinwire' Hence, Thinwire only allows 185meters
and 29 taps. So you do the math and determine how much is left.
Then you can attach additional thinwire stuff if you have leftover
distance and taps.
Mark
|
| 3766.7 | no workee | CSC32::D_PERRIN | | Fri Aug 09 1996 19:03 | 6 |
| The hub owners manual states that the hub counts for 15 nodes on
a thinwire segment, so do not connect anything between the hubs.
I've had customers try it and it doesn't work.
hub ----T-----hub = 31 stations out of a maximum of 30
vax
|