Technical information

Warranties and Notices
Approved Usage
The modem is approved only for use with the following facilities:
Storage of telephone numbers for retrieval by a predetermined code
Detection of initial proceed indication
Automatic calling
Tone detection
Modem
Operation in the absence of secondary proceed indication
Any other usage will invalidate the approval of your modem, if, as a result, it then
ceases to conform to the standards against which approval was granted.
The approval of the modem for connection to UK PSTN is INVALIDATED if the
apparatus is subject to modification in any material way not authorized by British
Approvals Board Telecommunications (BABT) or if it is used with, or connected to
Internal software that has not been formally accepted by BABT.
Installation
The IBM ThinkPad 755CX is manufactured to the International Safety Standard
IEC950 and as such is approved in the U.K. under the General Approval number
NS/G/1234/J/100003.
The IBM Data/Fax modem installed in the ThinkPad 755CX is approved separately
and has its own independent approval number.
This modem, supplied by IBM, does not contain excessive voltages. An excessive
voltage is one which exceeds 42.4 v peak ac or 60 v dc. It interfaces with the
ThinkPad computer using Safe Extra Low Voltages only. To maintain the
independent approval of the IBM adapters, it is essential that other optional cards,
not supplied by IBM, do not use main voltages or any other excessive voltages.
Seek advice from a competent engineer before installing other adapters not supplied
by IBM.
For your continuing safety, care must be take to ensure that the modem is only used
when mounted within the computer with all external covers fastened securely by
means of any screws supplied with your installation kit.
Users of this modem are advised that they are only approved for connection to the
PSTN via the interface supplied by IBM. Connection of a modem to the PSTN by
any other means will invalidate the approval.
General
These modems might not operate satisfactorily on a certain number of trunk routes.
Any persistent difficulties should be referred to IBM.
266 IBM ThinkPad 755CX User's Guide