Control Data Corporation CDC CC63X Hardware Maintenance Manual page 78

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SAM 8-1
SAM 8 INTERNAL MODEM PROBLEMS
Prerequisites: SAM 4 (Test 1 Resident Diagnostic) runs okay.
Terminal is connected to telephone line using a T connector and a
telephone handset is connected to the second jack of the T
connector.
Assumptions: Terminal is unable to connect or communicate with a
remotely located terminal or computer system by using its
internal modem. A second telephone handset with a different
phone number is located nearby and is available for test purposes.
A B
I I
001 Y N
002
003
004
005
006
007
008
2
A
6A-16
Y N
I I
I
1
Y N
I
1
Y N
I
1
1
NOTE
Some terminal installations never
use the auto-answer mode of oper-
ation. If the terminal under test
is such a terminal, skip the first
eight line items of this SAM and
begin testing with line item 009.
Does the modem work properly in auto-answer mode?
Answer to this question assumes dialogue with some-
one at a remote site who can call your terminal and
verify proper or faulty answer function of your modem.
Using the second telephone handset, call the modem.
Does the modem's telephone ring?
Refer to line item 012 for appropriate action.
Does the modem answer the call (go off hook),
and does it generate an answer tone?
Refer to line item 017 for appropriate action.
verify suspected auto-answer mode failure of your
modem via a second (different than one used in line
item 001) remote terminal or computer system. Does
auto-answer mode of your modem now work okay?
Refer to line item 017 for appropriate action.
Refer to line item 011 for appropriate action.
62940034 E