COURIER HIGH SPEED MODEMS
Data Mode Operations 4-27
&H3 Use both hardware and software flow control. If you are
unsure about what your equipment supports, select this
option. But keep the warning, above, in mind about
software flow control.
Received Data Flow Control
Separate commands, &Rn (hardware) and &In (software), con-
trol the flow of Received Data passed by the Courier to your
computer or terminal.
Your software and machine must support whichever type you
select, although we recommend hardware flow control, if
possible.
Hardware Control(&Rn)
&R0 Delay Clear to Send Response after Request to Send
signal (RTS/CTS delay). The delay is required by some
synchronous mainframes and does not apply to
asynchronous calls.
&R1 The modem ignores RTS. This setting is required if your
computer or terminal or software does not support RTS.
&R2 Hardware flow control of received data enabled.
Default. The modem sends data to the computer or
terminal only on receipt of the RTS signal.
Software Control (&In)
WARNING: In ordinary operation, the only characters the
modem recognizes during a call are the three pluses (+++) of the
escape code. But when software flow control is enabled, the
modem also looks for <Ctrl>-S or <Ctrl>-Q characters. If these
characters occur in a file or as part of a protocol, the modem
reads them as XON/XOFF characters and acts on them. In
some cases, the modem drops them from the data stream.
&I0 Disables XON/XOFF flow control of received data.
Default. Recommended for non-ARQ (Normal mode)
calls, but see &I5. The I0 option provides transparency
for all characters except the escape code sequence (+++),
because at this setting the modem does not look for
control characters.
