Getting status of DCE device from a DTE device

[Bill Stapleton]

In article <1991Apr29.211345.12615 at chinet.chi.il.us>, les at chinet.chi.il.us (Leslie Mikesell) writes:
> In article <8283 at alpha.cam.nist.gov> coleman at cam.nist.gov (Sean Sheridan Coleman X5672) writes:
...
> >I am trying to make sure that the port plugged into the 
> >back of my Sparc Station is hooked into something.
...
> To test for carrier detect being asserted, all you have to do is
> set a short alarm and attempt an open.  If the alarm hits before
> the open completes, you were blocked waiting for CD.  Or, with
> Suns you can open with O_NDELAY and use their ioctl() extensions
> to retreive the modem status.

This is probably obvious to all you experienced SUN people, but make sure
you don't have the "soft carrier" stuff turned on.  I helped hook a printer
up to a new Sparc Station, and as shipped, the soft carrier for the tty port
was locked on - So stuff would "print" whether the printer was on or off or
unplugged or ...

--
Bill Stapleton
     wls at csd4.csd.uwm.edu
     uwmcsd4!wls