USRobotics V.34 User Manual
Page 65
COURIER HIGH SPEED MODEMS
4-28 Data Mode Operations
NOTE: Because of the risk described in the above
warning, the settings that follow are only recommended
for users whose data does not include XON/XOFF
control characters.
&I1
The Courier acts on your typed XON/XOFF commands,
computer. Use in ARQ mode only, but keep in mind that
the XON/XOFF characters sent to the remote computer
may interfere with XON/XOFF signaling between the
remote computer and remote modem. See &I2.
&I2
The Courier acts on your XON/XOFF commands, but
removes them from the data stream instead of passing
them to the remote computer. This ensures that the
remote computer does not confuse your XON/XOFF
characters with those from its attached modem. This is
the recommended setting for ARQ mode.
However, if the call is not in ARQ mode, there is no flow
control on the phone link. If you send an XOFF to your
modem and it stops passing data, it has no way to tell the
remote computer and modem to stop sending for a
while, and your modem's buffer may overflow. For more
reliable control in non-ARQ mode, see &I5.
&I3
Hewlett Packard
Host mode. Applies only to modems
attached to an HP mainframe that uses the ENQ/ACK
protocol. Use in ARQ mode only. See Appendix G.
&I4
Hewlett Packard
Terminal mode. Applies only to
modems attached to terminals in an HP system that uses
the ENQ/ACK protocol. Use in ARQ mode only. See
Appendix G.
&I5
This setting is designed to enable flow control on the
phone link when the connection is not under error
control. For this to work for you, the remote modem
must also have &I5 capability.
In ARQ mode, a Courier set to &I5 operates the same as
it does when set to &I2. It acts on your XON/XOFF com-
mands, but does not pass them to the remote system.
The error control protocol enables the modems to control
the flow of data on the phone link.