Appendix: Answers to Frequently Asked Questions
40
MicroLink ISDN/PCC-16
Manual © 1997 ELSA GmbH
G
Answers to Frequently Asked Questions
General
How can I send AT commands to the ISDN adapter board?
To communicate with an ISDN adapter board via AT commands, you need a suitable communications
or terminal program supporting the INT14 mode (communications via the BIOS interrupt 14h), for
example
Telix
. After loading the CAPI and FOSSIL drivers and starting the communications program in
INT14 mode, you can enter AT commands which are then sent to the ISDN adapter board via the
drivers. See your
Telix
documentation for detailed information about the INT14 mode of Telix.
My ISDN adapter board does not accept any AT commands. Is the configuration wrong, or
is the board defective?
If entered AT commands are not displayed on the screen and/or not executed by the ISDN adapter
board, this can have several possible reasons. Please check the following settings:
n
Is your communications program set to INT14 mode? Many programs (e.g. Telix 3.50 and Telix
for Windows) must be expressly set to INT14/FOSSIL mode for the operation with ISDN adapter
boards.
n
Is your communications software set to the COM port used by the FOSSIL driver (cFos)?
n
If you have changed the configuration of your ISDN adapter board, try to restore the default
settings with the
AT&F
command (even if this command does not appear on the screen). With
this setting you should be able to enter an
AT
which is answered by the ISDN adapter board
with OK.
Can the CAPI or FOSSIL driver be loaded into the high memory area of my PC?
There are two ways to load the CAPI and FOSSIL driver into the high memory area. Under DOS the
drivers can be loaded into the high memory by means of the DOS command
LOADHIGH
. Under
Windows the drivers can be swapped to the extended memory via command line entries in the
WINSTART.BAT file.
Under DOS the memory managers HIMEM.SYS and EMM386.EXE (which are a part of DOS) provide
the possibility to load drivers into the upper memory area between 640 KB and 1 MB. HIMEM.SYS
and EMM386.EXE are included in the CONFIG.SYS and therefore loaded when the system is booted.
See your DOS documentation for more information about these memory managers. The DOS
command
LOADHIGH
(short form
LH
) can be called from the DOS prompt or included in the
AUTOEXEC.BAT file. For example, the Euro-ISDN CAPI can be loaded into the high memory above
640 KB with the command
LH DSS1CAPI
, making more conventional memory available for application
programs.
The DOS command
MEM
can be used to display the occupied and free memory and, with the
/c
option, to show the memory area the driver has been loaded into. If the available upper memory is not
sufficient to load a driver, DOS will try to load the driver into the conventional (lower) memory.
