User's Manual

25
2.0 Quick Start
2.5 Problem Solving
If you encounter difficulties in setting up or using the modem, try the
remedies described below. If you suspect a system malfunction, follow the
diagnostic procedures described in Chapter 7. If you cannot resolve the
problem, call your supplier.
1. A LL M ODES
Make sure all cables are properly connected to the back of the modem.
2. A LL D IAL M ODES (H AYES , V.25 BIS , D UMB , B ELL 208, AND V.32/208)
DTR (Data Terminal Ready) must be ON if you want to use the modem’s
autodial or auto-answer features. (If DTR is ON, the TR indicator is present
on the EIA status screen.)
3. A LL A SYNCHRONOUS M ODES
The modem’s default DTE speed is 38.4 Kbps in asynchronous mode. If the
local DTE does not support this speed, change the modem’s DTE Speed
option setting. In Hayes mode, the default DTE speed is automatically
overridden when the Modem is autobauded (the Hayes mode AT attention
code is sent to the Modem).
4. H AYES M ODE
In Hayes mode with default settings in effect, the Modem transmits result
codes (messages) to the DTE. In some instances, this may cause undesirable
interaction with the attached DTE. If such interaction occurs, use the AT Q2
command to suppress result codes for incoming calls.
5. A LL L EASED -L INE M ODES (2-W IRE , 4-W IRE , AND V.33)
DTR (Data Terminal Ready) must be ON for the units to train on the leased
line. (If DTR is ON, the TR indicator is present on the EIA status screen.)
Four types of compromise equalization are available to compensate for
distortion. If the signal quality appears to be inadequate (see Quality Screen
in Section 7.6.2), or if the modems are frequently retraining, try changing
the equalization option. See Compromise Equalizers in Section 3.3.6.
6. L EASED -L INE (E XCLUDING V.33 O PERATION )
Make sure one modem is set to originate mode and that the other is set to
answer mode. (If the correct Quick Setup is selected, and not incorrectly
modified, the answer/originate status should be correct.)