Linux-Hams archive - January 1998: Re: combat radio and ppp

Re: combat radio and ppp

Terry Dawson (grxv.wfcyrlsgcr@ras.ru)
Thu, 08 Jan 1998 09:06:19 +1100

M Norrby wrote:
>
> I am trying to establish contact between two RedHat 486:s.
> Both boxes have a combat radio with a radio modem attached
> to their serial port.
>
> Even if I start pppd with the silent option it activates RTS, which
> results in CD going inactive and CTS goes active. (Since the link is
> half duplex there is no way to both send and receive at the same time)
>
> How do I disable the feature that _always_ activates RTS? I don't
> want RTS when I am not sending data...
>
> I have tried ckermit, but the same problem arises there even if I set
> it to crtscts and half-duplex...
> The radios are connected ok. I _can_ transmit data in _one_ direction
> if I force the RTS low. The modems are supposed to be v.24 compliant.
>
> What should I do?

I'm not sure this is the best place for you to ask. But it sounds to
me like the "Combat" radio are like the STRIP/Metric dataradios. If that
is the case then you should probably be using the kernel driver for it.

The pppd 'silent' option has _nothing_ do with RTS, so it is not surprising
the enabling it made no difference.

Likewise with kernel and enabling CRTSDTS, and that will do is enable
hardware flow control, which does have to do with RTS but is still not
what you want.

I'm presuming you need RTS to be active when you are transmitting data
and to be inactive to receive. This is, I believe, what the STRIP kernel
driver does for you. But you won't be running PPP over it I don't think.

I think I actually wrote a section in the last release of the NET-3-HOWTO
that described how to configure these things and get more information
about them, you might try it:

http://sunsite.unc.edu/LDP/HOWTO/NET-3-HOWTO.html

regards
Terry