NEC SL1000 Features And Specifications Manual page 136

SL1000/SL1100
2. Dial #0.
If you hear error tone, your extension Class of Service prevents Universal Answer.
To listen to the incoming trunk ring choices:
1. Press Speaker key.
2. Dial 811 + 2.
3. Select the ringing (1~7) you want to check.
4. Go back to step 3 to listen to additional choices or press Speaker key to hang up.
To change the ringing of your incoming trunk:
C
1. Press Speaker key.
2. Dial 820 + 2.
3. Select the ringing (1~7).
4. Press Speaker key to hang up.
1-126
ISSUE 2.0
Central Office Calls, Answering