| Title: | Siemens Connectivity |
| Notice: | FTSIE Contact is Michael Eisenhut @MUC 865-1487 |
| Moderator: | UFHIS::MEISENHU |
| Created: | Tue Aug 30 1988 |
| Last Modified: | Mon Feb 19 1996 |
| Last Successful Update: | Fri Jun 06 1997 |
| Number of topics: | 195 |
| Total number of notes: | 512 |
With Null-Modem connections one of the Parties involved has to play
DCE.
Digital has no Problem there as one can define INTERFACE DCE with the
Profile ISO8208.
Siemens has also a semi-official (i.e. it's not documented but is given
to customers who ask for it) method to play DCE. It's crude but it
works.
Just for your information this is how they do it in case you're in a
position where you have to explain it to your customer or the local
Siemens support personnel.
The line that the VAX is connected to has 2 Line Tables (1 Input
& 1 Output) (German: Ein- und Ausgabe Leitungssteuertabellen)
associated with it in the PDN System. The line number and the
associated output line table is given by the Siemens Generation
parameter XLTNG LPUFADR=X%xx. The output line table word 11 contains
the relevant HDLC-LAPB addresses.
0 1
LW10 * * *
*****************
LW11 * 03 * 01 * Normal DTE Generation
*****************
LW12 * * *
All the Siemens System Manager has to do is to invert the above fields.
0 1
LW10 * * *
*****************
LW11 * 01 * 03 * Patched PDN System for DCE Operation
*****************
LW12 * * *
Hope this helps.
John
| T.R | Title | User | Personal Name | Date | Lines |
|---|---|---|---|---|---|
| 41.1 | NULL-MODEM means Modem-Emulator | MUNICH::KLOEPPER | Vera Kloepper/Net&Comms-Support | Fri Jan 05 1990 14:27 | 20 |
NULL-MODEM !!!
That type of connection doesn't mean, that there isn't any synchr.
modem.
To connect to a VAX synchr. controller you have to use a Pair of Modems
or a Modemeliminator.
=> The Modem-Connection alsways is in DTE mode also if the P.S.I. is
setup in DCE mode.
Don't forget this fact, when you are trying to connect inhouse a
synchr. line between any Siemens and any VAX.
(Note:
Siemens has a clock on every synchr. device and don't need
a external modem - and because of that mostly they don't
understand why they have to use it.)
regards Vera
| |||||
| 41.2 | WOODWARD'LAW: A theory is better than an explaination | MUNICH::DITE | Mon Jan 08 1990 21:01 | 10 | |
Sorry of course I meant to be more precise:
When the two devices communicate via a synchronous data link, the
transmit clock from each device is normally cross-connected and is used
as the receive clock by the other device. In some instances however,
neither device contains a clock source and the clock to be used
is generated within the null modem. The latter is known as a modem
eliminator.
John
| |||||