0049-2702-XXX Alliance Series Modems – USER MANUAL
08/05/2010
Rev. A
Page 40 of 197
Figure
2-1.
Flow
control
options
-
DTE-DCE Flow Control
Hayes, V.25bis, dumb, leased line modes (except V.33 and V.29)
DC1/DC3 (XON/XOFF)
Most common method of flow control. Inserts control characters
^S and ^Q into the data stream to stop (^S) and start/restart (^Q) the flow of data. (Also called
software, logical, or in-band flow control.)
NONE
No flow control. All flow control characters are passed through the communication
channel.
RTS
(RTS on/off) The Request to Send signal controls data flow from the modem to the
DTE. (RTS flow control is also called hardware, physical or out-band flow control.) This
selection enables flow control for the local modem only.
DC1/DC2
Inserts control characters ^R and ^Q into the data stream to stop (^R) and
start/restart (^Q) the flow of data from a device. (Also called software, logical, or in-band flow
control.)
Note: When using the modem for binary file transfer, in-band flow control (flow control
using control characters) must be disabled. In this case, use hardware flow control or, as
an alternate, lower the DTE speed to reduce the possibility of overflow.
