G. Flow Control Translation
154001UA
G-1
Normally, when a reverse flow control signal is received at one end of the
connection (typically the terminal end), an internal multiplexer control message
is sent to the other end to exert flow control upon the host. If both flow control
and flow control translation are set at the host end, then a channel converts a
reverse flow control internal message to the programmed flow control option.
For example, the terminal end multiplexer is configured for in-band flow
control and reverse flow control. The host end multiplexer is configured for
out-of-band flow control and reverse flow control and has flow control transla-
tion enabled. The terminal end multiplexer will stop transmission from the
terminal to the multiplexer using the in-band flow control (XOFF) character that
has been selected by the user. Transmission will be restarted using the specified
in-band (XON) character. Similarly, in this example, the terminal will stop and
start transmission from the multiplexer to the terminal using the specified in-
band reverse flow control (XOFF/XON) characters.
Upon receiving a reverse flow control (XOFF) character from the terminal, the
multiplexer will immediately suspend transmission to the terminal and send the
in-band reverse flow control character to the host end. The host end multi-
plexer will convert the in-band flow control XOFF character (initiated by the
terminal) to the specified out-of-band flow control signal for presentation to the
host. In this example, an ASCII XOFF character generated by the terminal will
cause the host end multiplexer to perform the appropriate out-of-band EIA
signaling to the host. It is important to remember that, in this example, the
translation takes place in the host end multiplexer (Figure G-1).
Figure G-1. Flow Control Translation
G.
G.
G.
G.
G. Flow Control T
Flow Control T
Flow Control T
Flow Control T
Flow Control Translation
ranslation
ranslation
ranslation
ranslation
XOFF
CTS-
2031G-1
3028 Turbo
S TATI STICAL
MUL TI PLEX ER
XOFF/XON
CTS-/CTS+
Flow Control Translation
CRT
HOST
3028 Turbo
S TATI STICAL
MUL TI PLEX ER