HP 3000 99x Family, Installation Manual

Page: 163 / 173

Appendix C C-13
Configuring the Remote Support Modem
Configuring Individual Modems
Supported cables:
■
Must use 92219Q modem cable.
Auto-dial modes: Hayes.
This modem does not work with v.22bis because it does not supply 112 and because the
sense of 111 is backwards (TRUE means low speed, FALSE means high speed). The
problem that 111 is backwards can be remedied by configuring the modem to ignore 111.
Change so that DTE Fallback is
Disabled
. This is the factory default. Not supplying 112
means that the Console/LAN card always thinks it is running at the lower speed. If you set
the speed for twice the desired speed, then it will work at the desired speed. It is best not
to use this modem with any of the CCITT bis protocols.
Settings
The Black Box defaults for all of the modem lines are incorrect and must be changed before
this modem will work properly. To do this from the front panel, go into the Change DTE
Parameters and set the following:
Responds to DTR
DSR is Normal
DCD is Normal
CTS follows RTS
This can be done with the following AT command:
AT&D2&S1&C1&R
For Hayes dialing, make certain that the AT command set is enabled. It is normally good
to disable status messages to the host by using the
ATQ1
command.
The current configuration can become the power-on configuration by using the
AT&W
command.
This modem does not do any rate shifting. So the DTE rate and the DCE rate must be the
same.
This modem seems to work in AP mode with the protocol set to either Bell or CCITT. It
does not work with the modem protocol set to CCITT_BIS. Make certain to configure the
modem to ignore 111, or configure the Access Port to set FS low. It also seems to work fine
in normal mode (i.e. under host control).
Multitech MT224EH7
Supported modes:
■
Bell
■
CCITT_OM
■
CCITT_AM
■
CCITT_BIS_OM
■
CCITT_BIS_AM