[sci.electronics] Modem Problem

hovan@bgsuvax.UUCP (John Hovan) (01/22/88)

	Can anyone offer a suggestion on ways to connect two 300baud modems
that do not have an answer switch so that a carrier can be generated on one
end?  Is it at all possible to emulate a carrier in software or is this 
reaching?  Please email or post any realistic solution to this problem.


These modems, if able, will be used to call a friend with an SE.  My machine
is also an SE.  Modems we have are ComData Model #305E2-12 which have a   
voice data switch on the front panel.


			Thanks,

				John Hovan
				Bowling Green State University
				Hardware Support
				hovan@bgsuvax.uucp
				N8JAA

tedk@ihuxv.ATT.COM (Kekatos) (01/30/88)

In article <1518@bgsuvax.UUCP> hovan@bgsuvax.UUCP (John Hovan) writes:
>
>
>	Can anyone offer a suggestion on ways to connect two 300baud modems
>that do not have an answer switch so that a carrier can be generated on one
>end?  Is it at all possible to emulate a carrier in software or is this 
   NO
>reaching?  Please email or post any realistic solution to this problem.
>
>
>These modems, if able, will be used to call a friend with an SE.  My machine
>is also an SE.  Modems we have are ComData Model #305E2-12 which have a   
>voice data switch on the front panel.
>
>
>			Thanks,
>
>				John Hovan
>				Bowling Green State University
>				Hardware Support
>				hovan@bgsuvax.uucp
>				N8JAA


Don't understand your problem.

Answer end:
Connect your modem to the phone line. Put the switch on the front to data.
It ought to answer the when the phone rings. Thus generating carrier.


Do you have a manual for modem?






Ted G. Kekatos
backbone!ihnp4!ihuxv!tedk                     (312) 979-0804
AT&T Bell Laboratories, Indian Hill South, IX-1F-460
Naperville & Wheaton Roads - Naperville, Illinois. 60566 USA

nather@ut-sally.UUCP (Ed Nather) (02/01/88)

In article <1518@bgsuvax.UUCP>, hovan@bgsuvax.UUCP (John Hovan) writes:
> 
> 
> 	Can anyone offer a suggestion on ways to connect two 300baud modems
> that do not have an answer switch so that a carrier can be generated on one
> end? 

If they are "Hayes compatible" and have the full command set, you can
make one into an "answer" modem with the command

    ATD (phone #)R

After dialing the number, the modem goes into answer mode.  It's for
calling modems that are "originate only."  If the modems are directly
connected, use "ATDR" on one, and "ATD" on the other.

Note that this only works at 300 baud ...

-- 
Ed Nather
Astronomy Dept, U of Texas @ Austin
{allegra,ihnp4}!{noao,ut-sally}!utastro!nather
nather@astro.AS.UTEXAS.EDU

wcf@psuhcx (Bill Fenner) (02/01/88)

In article <10276@ut-sally.UUCP> nather@ut-sally.UUCP (Ed Nather) writes:
>In article <1518@bgsuvax.UUCP>, hovan@bgsuvax.UUCP (John Hovan) writes:
>> 	Can anyone offer a suggestion on ways to connect two 300baud modems
>> that do not have an answer switch so that a carrier can be generated on one
>> end? 
> {explains Hayes-compatible way}

I believe that the modems that John is talking about are simply origionate-
only modems which pick up the phone and turn on their carrier when the
voice - data switch is flicked to data.  If there is no answer switch, then
no, you can't connect the modems, unless of course you open up one of them
and muck around with the frequencies.  (it's loads of fun. :} )

   __      _  _      _____   Bill Fenner      wcf @ psuhcx.bitnet
  /  )    // //       /  '                    wcf @ hcx.psu.edu
 /--<  o // //     ,-/-, _  __  __  _  __     ihnp4!psuvax1!psuhcx.bitnet!wcf
/___/_<_</_</_    (_/   </_/ <_/ <_</_/ (_

david_islander_hughes@cup.portal.com (02/02/88)

We work with this problem EVERY DAY. It's really quite simple.
On  ome machine you type (caps)     "ATA"

on the other machine type (caps)
"ATO"

Of course, this assumes Hayes compatability.

We use this to input/put news stories  TRS80 laptops<->Macs. It works
well and no sweat, no null modem, etc.

Hafa Adai from Saipan, Mariana Islands  Y'all.
Marianas Variety News and Views Newspaper
Serving Micronesia since 1972