Multitech MultiModemISDN MTA128ST-USB, Руководство пользователя

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MultiModemISDN User Guide
MTA128ST-USB
• The MTA128ST-USB may be defective. If you have another Multi-Tech MTA128ST-
USB, try swapping units. If the problem goes away, the first MTA128ST-USB is
possibly defective. Call Tech Support for assistance (see Chapter 6).
The MTA128ST-USB dials but cannot make a connection
There may be several reasons the MTA128ST-USB fails to make a connection.
Possibilities include
• Lack of a proper physical connection to the communication line.
• A busy signal.
• A wrong number.
• No terminal adapter at the other end.
• A faulty communications device, computer, or software at the other end.
• Incompatibility between communications devices.
• An improperly configured MTA128ST-USB.
Narrow the list of possibilities by using extended result codes. To enable them, enter
ATV1X2 and press ENTER while in terminal mode or include V1X2 in the MTA128ST-
USB’s initialization string (V1X2 is enabled by default). When you dial again, the
MTA128ST-USB reports the call’s progress.
• If the MTA128ST-USB reports NO DIALTONE, check that the ISDN S/T cable is
securely connected to both the unit’s ISDN jack (not the AUX jack) and the ISDN
network terminator or wall jack. If the cable looks secure, try replacing it. If that
doesn’t work, the problem may be in your building’s telephone installation. Make sure
ISDN cables on all devices are wired straight-through (pin 1 to pin 1, pin 2 to pin 2,
etc.) and do not have reversed pairs. The cable must have at least the middle four
pins (pins 2, 3, 4, and 5) connected. A reversed pair on the U (phone company) side
is not important, but a reversed pair on the S/T (your) side can create problems if you
have more than one device, since multiple devices attached to the S/T interface must
all have the same polarity.
• If the MTA128ST-USB reports BUSY, the other number may be busy, in which case
you should try again later.
• If the MTA128ST-USB reports NO CARRIER, no connection was made. You might
have dialed the correct number but the other computer or software was turned off or
faulty. Check the number and try again, or try calling another system to make sure
your unit is working. Also, check that you accurately configured the TA with the
correct switch type, TEIs, data protocols, and other parameters needed for a
successful call (see Chapter 3).
You can place data calls but not voice calls or vice versa
• You might not have ordered both voice and data service from your ISDN provider.
Check your contract or latest statement of service from your ISDN provider.
• Your ISDN provider may have programmed the switch incorrectly. Call the provider.