Asynchronous Troubleshooting; Modem Pooling; Power Failure; Troubleshooting Symptoms And Solutions - Nortel Meridian M3905 User Manual

Asynchronous troubleshooting

If data is sent in idle mode (when there is no active call), you can not use keypad
dialing. You must stop sending the data from the DTE.
You must disconnect pin 22, if you are using an RS-232 cable to connect the MCA
to an ADM3/5 terminal.
If you are changing the MCA from Synchronous to asynchronous, change the baud rate
before you change the mode from synchronous to asynchronous.
Some terminals drop DTR with this mode change. If this happens, the display does not
show RELEASED.
Before you select VLL you must program Auto Dial.
The receiving data module always adapts to the sending data parameters. The
sending data module never adapts to the answering data module parameters.

Modem pooling

Synchronous mode does not support modem pooling.

Power failure

When there is an active call between two MCAs, a power failure on either side
does not disconnect the call. The call connection remains until the power returns.
The MCA always retains the previous data parameters. There is no resetting
required in the case of power failure.

Troubleshooting symptoms and solutions

Symptom
No response when you
type <CR> or AT at the
terminal.
Asynchronous troubleshooting
Solution
Dial ¤°to make sure you are in terminal mode.
1.
2. Make sure your PC or terminal's power is on and you are on-line.
3. You need to connect a null modem cable between your MCA, if the
equipment is not configured as Data Terminal Equipment.
4. Make sure the MCA is receiving external power. Check the power
cable, make sure the connection is secure and there is power.
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