DSU Operations
5-413610-A2-GB41-60 March 1999
The Add command is executed. A message is sent to
the control DSU asking that the tributary be added to the
polling list. The control DSU responds by acquiring the
tributary DSU onto its polling list.
Acquiring the Poll List
The first time the MCMP capability is activated on the
network or after the network has been reconfigured, the
Acquire Poll List (Acq) command must be issued from
the control DSU’s DCP to activate an initialization
process. During the initialization process, the control
DSU-MCMP performs the following tasks:
•Determines which tributaries are present on the
network.
•Determines the roundtrip delay to each tributary.
•Loads whatever values have been assigned to the
channel speed and asynchronous configuration
options at the control DSU into each of the
tributaries.
The initialization process typically takes less than
8 seconds to complete.
Once the control DSU determines the roundtrip delay
for a tributary, it sends that information to the tributary.
The tributary uses this information to determine when it
should send data upon being polled by the FEP.
To acquire the Poll List, press the key once.
Displ
F1
Poll List:
Clr Chang Add
F2 F3
Acq
Press the key to display Acq.
Clr Displ
F1
Poll List:
Chang Add Acq
F2 F3
F1
Acquir Poll List:
Command Complete
F2 F3
All tributary addresses have been acquired.

Directory

The DSU’s dial backup Directory (Dir) is available
only if a DBM is installed, and only from the Local
branch. It can store up to 10 dial strings so the DBM-V,
DBM-S, or DBM-D can call other DBMs or modems.
Each entry consists of a telephone number and may
include other information, such as a callback directory
pointer and a comment field.
A Backup Directory telephone number or dial string
can contain any of the characters listed in Table 5-12.
Refer to COMSPHERE 3600 Series Data Service Units,
Models 3610 and 3611, Dial Backup Module,and SNA
Diagnostic Options, Applications Guide to learn how to
access this subbranch, and for examples showing how to
enter a dial string, to change it, to clear it, and to copy one
directory entry into another.
Remember that a dial string can be up to 36 characters
and cannot contain any separating characters or spaces
(i.e., 555-1234 or 555 1234). Other valid characters can be
interspersed: *, #, t, p, w, and comma (, ). The Undo
selection restores or erases the dial string. Entering an
underscore (_ ) to the immediate right of the last
character ends the field. After a directory entry has been
entered or changed, save the entry.
CAUTION
Do not use

Save

until after
you have loaded the directory
entry displayed and, if
necessary, edited the
directory entry. Saving before
a directory entry is loaded
overwrites the current
directory entry with random
characters.