
as data from the keyboard will also stop data from the TNC. And likewise, if
there is a <Ctrl+S> in a file being sent, data flow from the TNC will stop until a
<Ctrl+Q> is received.
XFLOW needs to be turned ON for the TNC to use software flow control. XOFF
determines the character sent by the TNC to stop the flow of data from the com-
puter, and the XON character restarts the flow. The TNC expects the computer to
send the STOP character to stop data to the computer and the START character to
restart data. To use software flow control these commands would be set as fol-
lows: XFLOW ON, XOFF $13, XON $11, STOP $13, START $11. (Default set-
tings.)
Two commands are provided to make it possible to send and/or receive these spe-
cial characters in Transparent Mode and still use software flow control.
TXFLOW enables flow control sent by the TNC to the computer and TRFLOW
enables the TNC to recognize flow control sent by the computer. If both these
commands are ON (and the above commands are set as stated) then software
flow control will take place in both directions, to and from the TNC and com-
puter.
+ If you are in Transparent Mode sending a file, the computer does not need to tell
the TNC to stop and start (since you are sending the file). By turning TRFLOW
OFF and TXFLOW ON, the TNC will accept START and STOP characters em-
bedded in the file and send them along to the radio as data. Meanwhile, the TNC
can send the XOFF and XON characters to the computer to control the flow of
data from the computer. When receiving a file, turn TRFLOW ON and TXFLOW
OFF; the computer will accept all data and use START and STOP characters to
control the flow of data from the TNC.
Hardware Flow Control
Hardware flow control monitors the voltages on the RTS and CTS pins of the
RS-232 cable. Therefore these two pins must be wired between your TNC and a
connected computer. The TNC holds CTS high as long as it can receive data.
Once its buffer gets full, it pulls this line low. The computer program monitors
this line. When it is pulled low, it knows to stop sending data. When the line is
again pulled high by the TNC, the computer program will restart sending data.
On the other hand the computer holds RTS high as long as it can receive data and
pulls it low to tell the TNC to stop sending data. The TNC always uses hardware
Overview of Packet Communication
Packet Modes of Operation
KAM’98 v 8.3
155
User’s Guide
Содержание KAM 98
Страница 4: ...User s Guide ii KAM 98 v 8 3...
Страница 18: ......
Страница 132: ...Getting Started Other Topics User s Guide 114 KAM 98 v 8 3...
Страница 160: ...blank page Non Packet Modes of Communication RTTY Operation User s Guide 142 KAM 98 v 8 3...
Страница 342: ...blank page Command Reference KAM 98 Commands User s Guide 324 KAM 98 v 8 3...
Страница 376: ...ASCII Chart paste in page 1 of 2 ASCII chart Appendix E Additional Information ASCII Chart User s Guide 358 KAM 98 v 8 3...
Страница 378: ...KAM 98 Parts Layout Appendix E Additional Information KAM 98 Parts Layout User s Guide 360 KAM 98 v 8 3...