[comp.dcom.modems] Problem with ARK 2.4K Plus Modems

kanaitis@cisunx.UUCP ( Kanaitis) (06/24/88)

My company just purchased a few ARK 2.4K Plus Dial modems, which I have
installed on our VAX/VMS system.  The modems work very well, except for
one small problem.  We have quite a few old-style Hayes Smartmodem 1200's
(the one's with only one phone jack in the back, and a volume knob) that
will be dialing into the ARKs.  These older hayes modems do not seem 
to recognize the valid carrier tone on the ARK, when the ARK is set to
autobaud down to 1200 baud.  Newer Hayes 1200 modems WILL work properly
with the ARKs, and the old-style Hayes will work with other 2400 baud
modems (such as the Hayes 2400s) on the VAX end.

Has anyone ever encountered a similar situation?  Any help would
be appreciated.

Thanks...

Pete Kanaitis
System Manager
Allegheny-Singer Research Institute
Pittsburgh, Pennsylvania
X979PK0P@VB.CC.CMU.EDU 
X979PK0P@CMCCVB.Bitnet
kanaitis%unix.cis.pittsburgh.edu@VB.CC.CMU.EDU
...!cisunx!kanaitis

cmr@m2-net.UUCP (Chuck Rader) (06/30/88)

Hayes and compatible 1200 bps modems often have problems connecting to
certain 2400 bps and Vadic triple 1200 bps modems.  The problem can be that
the answering modem cycles through the various carrier tones too quickly
without staying at one frequency long enough for the Hayes to lock on to
it.

Try setting the Hayes S-registers to shorten the amount of time the Hayes waits
before recognizing a carrier and lengthen the amount of time before it
detects a dropped carrier.
-- 
Chuck Rader, Manager, Computer Technical Services, University of Detroit
voice:  313-927-1349                  I don't worry 'bout a thing 'cause 
fax:    313-927-1011                  I know nuthin's gonna be all right
e-mail: cmr%m-net@umix.cc.umich.edu