ddc@druky.UUCP (CusterDD) (02/17/84)
================================== I have a desk-top micro running UN*X 5.0. I also have a digital phone with data connection (System 85). I want uucp (et.al.) to be able to dial out. To get the phone's (switch's) attention, one must send a break signal. Question: how does one get the (acu?) software (names, please) to generate the break signal to get the switch's attention. Incidentally, once the connection is made, the break signal is passed thru unchanged, i.e., the phone system becomes transparent to breaks. A corollary question involves the hangup procedure. To hang up, the DTE (computer) must diddle one of the RS-232 lines, probably the DTE ready line. The switch then disconnects. Question: how does an application level program signal to UN*X or the driver or whatever s/w in the loop that the appropriate RS-232 line is to be diddled? Close the device/file? At this point I don't know which line it is, but a little experimentation will quickly tell (I do know that pulling the plug causes the disconnect). I really don't want to hear that I have to write a special device driver. :-) David Custer AT&T-ISL, Denver, 30F103 (303) 538-3517 druky!ddc
fair@dual.UUCP (Erik E. Fair) (02/20/84)
The quick answer is that there is an ioctl(2) call in System V for
generating breaks. The catch is that the code is expected to be
in your serial driver (i.e. the top level tty driver does not fake it).
So if your serial driver doesn't know how to do a break, you will have
to fake it a la UUCP: change the baud rate down to 50 baud, and send
some number of nulls. (This was V7 UUCP. System III & later UUCP's
use the ioctl).
The ioctl is TCSBRK.
Erik E. Fair
dual!fair@BERKELEY.ARPA
{ucbvax,ihnp4,cbosgd,amd70,zehntel,fortune,unisoft,onyx,its}!dual!fair
Dual Systems Corporation, Berkeley, Californiaedwards@uiucuxc.UUCP (02/22/84)
#R:druky:-61300:uiucuxc:29300007:000:437
uiucuxc!edwards Feb 21 23:50:00 1984
You might want to look at ioctl(2) and tty(4) if you're
running 4.1 bsd. I think TIOCSBRK and TIOCCDTR will be of interest
along with their counter parts TIOCCBRK and TIOCSDTR. Assuming that
DTR is the signal line that you want to toggle and that TIOCSBRK does
send a break!
Alan Edwards
US Army Corps of Engineers
Construction Engineering Research Lab (CERL)
UUCP {...,ihnp4,pur-ee}!uiucdcs!uiucuxc!edwards