Nortel DMS-100 Series Maintenance Manual page 396

9-32 Trouble isolation and correction
17 The SMS sends the RCS a message to remove termination.
18 The SMS signals the RCS to test +T ringing and scans for off-hook. The
19 The echo return loss test uses TTU to determines if absorb termination
20 The SMS sends the RCS message to terminate channel test and sends
21 The diagnostic is complete.
Coin test sequence
The test sequence for a coin card follows:
1 The SMS sends the RCS a channel test setup request.
2 The RCS connects the absorb-PTPG termination.
3 The SMS sends negative loop mode A-B bits and scans for off-hook.
4 The RCS detects termination as off-hook and sends off-hook A-B bits.
5 The echo return loss test uses TTU.
6 The SMS sends on-hook message to the RCS to remove termination,
7 The RCS detects termination removal as on-hook and sends the SMS an
8 The SMS signals the RCS to test –R ringing and scans for off-hook. The
9 The channel loss test uses the TTU.
10 The noise test uses the TTU.
11 The SMS sends an on-hook message to the RCS to remove termination.
12 The SMS signals the RCS to test coin collect. The RCS connects the
13 The SMS sends negative loop mode A-B bits and scans for off-hook.
14 The SMS signals the RCS to run a positive coin check. The RCS sends
15 The SMS sends negative loop mode A-B bits, while echo return loss test
297-8231-550 Standard 09.01 August 1998
RCS connects absorb-PTPG termination, detects termination as off-hook
if +T ringing is present, and signals off-hook to the SMS.
made.
idle A-B bits.
sends negative loop mode A-B bits, and scans for on-hook.
on-hook A/B pattern.
RCS connects the reflect termination if the –R ringing is present and
detects termination as off-hook, signals off-hook. The SMS sends
negative loop mode A-B bits.
absorb-PTPG termination and sends coin ground A-B bits.
The RCS detects termination off-hook if channel unit provides positive
coin control voltage and sends off-hook A-B bits.
coin ground A-B bits.
uses the TTU. The test determines if the correct termination occurs.