[comp.dcom.telecom] System-X Exchanges

abm88@ecs.soton.ac.uk (Morley A.B.) (12/21/90)

I have found a new command on my local system-X exchange:  175

Does anyone know what it does? I get a message telling me what number
I'm calling from then some sort of test starts.

Replies via email if possible, thanks!  I'll summarise if anyone
wants.

On another note, I ordered a couple of star services (by phone of
course!)  and got then in under an hour! Well done BT!


Andrew Morely

martin@cellar.bae.bellcore.com (Martin Harriss (ACP)) (12/21/90)

In article <15551@accuvax.nwu.edu> abm88@ecs.soton.ac.uk (Morley A.B.)
writes:
X-Telecom-Digest: Volume 10, Issue 894, Message 8 of 10

>I have found a new command on my local system-X exchange:  175

On BT's mechanical exchanges, 175 is the code for the Subscribers
Automatic Line Test (SALT).  You have stumbled on the System-X
equivalent of this.

The way it works for mechanical exchanges is this:

Dial 175 X(XX) YYYY where YYYY is the last four digits of your number.
You may also need the access code X(XX), depending on where you're
doing this from.  Possible codes are 1, 2, 3,... 8, 9, 01, 02,... 09,
001, 002,... 005.  (Yes, the SALT machine counts pulses on a
25-position uniselector!)

Wait for the announcement "Start Test".

Hang up and wait for the phone to ring you back.

Pick up the phone and dial 1305.  You will now hear an announcement of
the test result.  If all is ok, you will hear "Testing OK".  There are
other announcements if something is wrong.

Other 130X combinations will do things like switch you to the test
desk or to the regional repair centre.

The reason for the access code and the last four digits of your number
is to tell the SALT machine which exchange and line you want tested.
(One SALT machine does for many echanges.)

Since System-X is electronic, that information is available to the
switch.

I suggest you try the following:

Dial 175, wait for the "Start test" announcement.  Hang up, wait for
the phone to ring.  Pick up, dial 1305.

Let me know if this works.

Note: In director areas you don't need the access code, since the
director generates it for you as part of the translation.  However,
some director exchanges use 185 or some other 17X or 18X as their SALT
code to distinguish between two or more exchanges using the same
director.


Martin Harriss    martin@cellar.bae.bellcore.com