romain@pyrnj.uucp (Romain Kang) (07/29/88)
I've been using modems from Telebit for over two and a half years now,
mostly with the old Telebit TrailBlazer. Recently, I've started running
a TrailBlazer Plus, and have started seeing problems that never occured
with the old TB.
For no apparent reason, the TB+ will freeze up and respond to
practically nothing except cycling power or the reset switch. Under
these circumstances, incoming calls will not be answered even though
DTR is high, and outgoing calls cannot be placed because all AT
commands are completely ignored. During all this, the LEDs on the
front behave normally -- they detect *all* RS232 signals correctly.
The only ways to get them out of this condition are to cycle power or
to use the hardware reset switch. (Before this, I would not have so
easily considered a paper clip a "tool.") After cycling power, the
TB+ acts as if nothing ever happened -- the configuration looks the
same as before, and
This has happened to two modems. The first came factory fresh as part
of the USENET promotion, and never worked properly, although its twin
(one serial number lower) has always behaved perfectly. Telebit
exchanged the defective unit for another unit that behaved for almost a
month, and then about two weeks ago started to exhibit the same problems
as the first.
If anyone else has had such experiences, both Telebit Tech Support and
I would like to hear about it. You can send mail to telebit!modems
(and pyrnj!romain, if you like) or call Telebit directly.
--
Romain Kang {allegra,cmcl2,pyramid,rutgers}!pyrnj!romain
Pyramid Technology Corp. / 10 Woodbridge Center. Dr / Woodbridge NJ 07095
"Eggheads unite! You have nothing to lose but your yolks!" -Adlai Stevensonrpw3@amdcad.AMD.COM (Rob Warnock) (07/31/88)
Hmmm... maybe this is a new & interesting problem... but it's not yours alone.
Last weekend, several TB+'s at AMD (amdcad.amd.com) "locked up" exactly as
you described (*NOTHING* until you power-cycle), and when I got home (about
25 miles away) I discovered that the TB+ on "redwood.uucp" had locked up
exactly the same way. Coincidence?
Hasn't happened before or since. These are all new 4.0 units, bought within
the last 3 months.
(By the way, fix this with power cycling, not the paperclip reset, or else
you'll revert to factory settings. While the EEROM settings are not lost,
on some hosts you can't talk to the modem with factory settings! If you
have set S52=2, so that settings revert on DTR-down, you'll also get your
EEROM settings back when you power-cycle out of the "hang". Worked for me...)
Rob Warnock
Systems Architecture Consultant
UUCP: {amdcad,fortune,sun}!redwood!rpw3
ATTmail: !rpw3
DDD: (415)572-2607
USPS: 627 26th Ave, San Mateo, CA 94403johnl@n3dmc.UU.NET (John Limpert) (07/31/88)
In article <22499@amdcad.AMD.COM> rpw3@amdcad.UUCP (Rob Warnock) writes: >Last weekend, several TB+'s at AMD (amdcad.amd.com) "locked up" exactly as >you described (*NOTHING* until you power-cycle), and when I got home (about >25 miles away) I discovered that the TB+ on "redwood.uucp" had locked up >exactly the same way. Coincidence? Probably not a coincidence. I've had the same thing happen to my TB+ with the 4.0 ROM's. The TB+ appears to have a problem with power supply output sequencing/reset. Short power hits from thunderstorms will put the modem in zombie mode. I just cycle the power and that fixes it. I have had similar problems with other equipment. If the power supply was designed properly, the modem would keep on running or reset itself, dependent on the severity of the power hit. I'm not an engineer, but some power supplies monitor the AC input voltage and DC output voltages. The power supply can generate a POWER OK signal to the equipment and/or shutdown the DC output if it is out of spec. If done properly, this prevents this type of problem. I hate having a system go down over a weekend because of a power glitch. The system stays down until someone comes in on monday morning and resets the equipment. -- John A. Limpert UUCP: johnl@n3dmc.UUCP, johnl@n3dmc.UU.NET, uunet!n3dmc!johnl PACKET: n3dmc@n3dmc.ampr.org n3dmc@wa3pxx
chris@mimsy.UUCP (Chris Torek) (08/01/88)
Ours seem to get this way exclusively after power failures and brownouts (usually due to thunderstorms), and then only on occasion. Given that other equipment (such as terminals and VAXen) behaves similarly, I tend not to see this as much of a problem---when something gets hung, you reset it.... -- In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 7163) Domain: chris@mimsy.umd.edu Path: uunet!mimsy!chris
james@bigtex.uucp (James Van Artsdalen) (08/01/88)
In article <22499@amdcad.AMD.COM>, rpw3@amdcad.UUCP (Rob Warnock) wrote: > [...] If you > have set S52=2, so that settings revert on DTR-down, you'll also get your > EEROM settings back when you power-cycle out of the "hang". Worked for me...) Interestingly enough, this *doesn't* always work for me. bigtex sits on my desk and I can hear the modem speaker while I work. I have it set to answer PEP-tones first (to encourage uucp neighbors :-), but on some rare occassions, the modem will go immediately to the 2400bps tones and not give the moose call. One thing that comes to mind is that to call some systems I usa the S50 register to lock the data rate at 1200bps (the local Telenet nodes answers at 2400 but I want to connect at only 1200bps). I have S52=2 also, and have a two second pause after DTR is dropped to ensure that the modem sees it, yet apparently it doesn't always take. I don't have the "catatonic" problem. I do have trouble with sending the modem "AT\r" sequences - it often acts as though it saw an "ATA" command. I still strongly recommend the TB+ - at ~$650 it's the only way to go (at $1250+ though, I'm not so sure). -- James R. Van Artsdalen ...!ut-sally!utastro!bigtex!james "Live Free or Die" Home: 512-346-2444 Work: 328-0282; 110 Wild Basin Rd. Ste #230, Austin TX 78746
jbayer@ispi.UUCP (id for use with uunet/usenet) (08/01/88)
In article <407@n3dmc.UU.NET>, johnl@n3dmc.UU.NET (John Limpert) writes: > Probably not a coincidence. I've had the same thing happen to my TB+ > with the 4.0 ROM's. The TB+ appears to have a problem with power supply > output sequencing/reset. Short power hits from thunderstorms will put > the modem in zombie mode. I just cycle the power and that fixes it. I > have had similar problems with other equipment. If the power supply was > designed properly, the modem would keep on running or reset itself, > dependent on the severity of the power hit. I'm not an engineer, but While I would agree with the possibility of the power supply, I would never run a un*x system without a standby power supply. The SPS should maintain the voltage within certain levels, and ideally should do a switch-over within 4-8 milliseconds. For those people who are really paranoid you can get an uninterruptable power supply for about twice the money. Using either a UPS or an SPS should solve any and all problems related to the ac line. Jonathan Bayer Intelligent Software Products, Inc. 19 Virginia Ave. Rockville Centre, NY 11570 uunet!ispi!jbayer
howardl@wb3ffv.UUCP (Howard Leadmon ) (08/02/88)
In article <1461@pyrnj.uucp>, romain@pyrnj.uucp (Romain Kang) writes: > > For no apparent reason, the TB+ will freeze up and respond to > practically nothing except cycling power or the reset switch. [misc. test omitted] I too have experienced this problem, but since I have had so many crazy things happen to my system, and a flip of the on-off switch was a valid cure, I just dismissed it. > This has happened to two modems. The first came factory fresh as part > of the USENET promotion, and never worked properly, although its twin > (one serial number lower) has always behaved perfectly. Telebit > exchanged the defective unit for another unit that behaved for almost a > month, and then about two weeks ago started to exhibit the same problems > as the first. Hopefully Telebit was good about his one, as I had one go brain-dead as well and they replaced it quickly for me. I have alos seen several other interesting problems crop up from time to time. Has anybody here on the net seen the modem not respond to calls when they are placed ?? I have called several remote systems and when the remote starts sending PEP tones my blazer just sits there and ignores it. Also at other times I have seen two blazers keep repeating the PEP startup sequence untill one of them times out and gives up. Generally the two that I have work fine, but sometimes I really have to wonder about the modems, and if there really is a problem. This is not supposed to be a flame, as even with the slight amount of flakieness that they exibit, I would still recomend the product as it is a real time saver.. > If anyone else has had such experiences, both Telebit Tech Support and > I would like to hear about it. You can send mail to telebit!modems > (and pyrnj!romain, if you like) or call Telebit directly. Well here is my followup, and I am sure they watch this group, at the same time I will also forward a copy to telebit!modems... ------------------------------------------------------------------------------- UUCP/SMTP : howardl@wb3ffv | Howard D. Leadmon PACKET : WB3FFV @ W3ITM | Fast Computer Service, Inc. IP Address: 44.60.0.1 | P.O. Box 171 Telephone : (301)-335-2206 | Chase, MD 21027-0171
rob@rtmvax.UUCP (Robert Talley) (08/02/88)
In article <151@ispi.UUCP> jbayer@ispi.UUCP (id for use with uunet/usenet) writes: >In article <407@n3dmc.UU.NET>, johnl@n3dmc.UU.NET (John Limpert) writes: > >> Probably not a coincidence. I've had the same thing happen to my TB+ >> with the 4.0 ROM's. The TB+ appears to have a problem with power supply >> output sequencing/reset. Short power hits from thunderstorms will put >> the modem in zombie mode. I just cycle the power and that fixes it. I >> have had similar problems with other equipment. If the power supply was >> designed properly, the modem would keep on running or reset itself, >> dependent on the severity of the power hit. I'm not an engineer, but >While I would agree with the possibility of the power supply, I would never >run a un*x system without a standby power supply. I agree completely with the last statement, but to clear up some of the confusion, my trailblazer *still* has this problem and it *is* on a ups along with the cpu & disks. I have been sitting right next to the modem when it decides to play this trick, and I can safely say that out of 15 devices running, most *not* on the ups, I *do not* think that power glitches are the complete answer to this problem. I have even seen my modem *speak* to itself for hours on end. No "SD" or "RD" lights, but the modem is asserting "CD" and it *thinks* there is another modem on the other end. Unplugging the telephone line from the modem does not even clear the condition. The poor user on the other end has called by voice to complain that "i got a burst of garbage (oxoxoxoxo) and had to hang up because it would not stop". Here again, like with some other sites, this problem has appeared after a month or two of *flawless* operation of the modem. Has anyone else seen this kind of behaviour? Robert Talley -- Robert Talley: RTmVax Semi-Public UNIX/USENET System Orlando, Florida UUCP: {uiucuxc,hoptoad,petsd}!peora!rtmvax!rob c/o: Alexander Financial; 7 W. Main STE:200; Apopka, FL 32703 (407) 880-0000