atcomsystems.ca/forum Forums Computers & Programming Computers, Software, Accessories Modem commands

Ofcourse there's also the option of uninstalling the comm software and then the modem from Device Manager. It HAS to happen in that order. Then re-install them in opposite order.

When I mentioned updates, I didn't mean updates you're aware of. Maybe the comm software auto-updated itself? Maybe another program updated/replaced the Windows serial driver? Maybe a new piece of hardware is responsible? Maybe the modem driver is set to "call home" and updated itself or/and the modem ".inf" (settings) file?

I don't mean to be nit-picking but I think the X1 command will make the modem to not report the non-existence of dial tone to the terminal, it does not tell it to disregard it.

If I recommend again to look at the modem "Properties" in the Device Manager as I mentioned previously. The Modem tab has an entry for Dial Control. That's another place to tell the modem not to wait for dial tone.
Then move to the Diagnostics tab and "Query" the modem. That's the equivalent of all AT&V and all ATI commands together. The very first line in that little window is the current init string for the modem. Also check "Append to Log", and then view the log.

Good luck!

Here's a cut/paste of what AT&V1 returned after a failed call attempt:

OK
atdt96586699,#499 (Call dropped immediately here after last digit was dialed)
NO CARRIER
at&v1
ACTIVE PROFILE:
E1 L3 M1 Q0 T V1 X1 &C1 &D1 &G0 &T0 &P0
S00:000 S01:000 S02:043 S03:013 S04:010 S05:008 S06:002 S07:001 S08:013
S10:014 S12:050 S16:000 S18:000 S29:070

STORED PROFILE 0:
E1 L3 M1 Q0 T V1 X1 &C1 &D1 &G0 &T0 &P0
S00:000 S02:043 S06:002 S07:001 S08:013 S10:014 S12:050 S18:000 S28:000
S29:070

ERROR

Oh, and to SPH: You are not nitpicking at all. Any suggestions that you have made are greatly appreciated.

I see that the AT&V1 reports the profile rather than the line conditions. This must be a US Robotics or other brand that doesn't use the Rockwell chipset. Exactly what brand is it? Issue an ATI7 command if you're unsure.

Regardless of the make, I'd say the S007 register value is way too low. Strap it to something like 60 (ATS7=60) before making another test call.

If your modem gives up again, send an ATS86? command and see if the Call Failure Code is reported there instead. The code will likely be a number rather than text.

I don't like that "ERROR" response at the end of the profile list; "OK" was expected. I'm not sure if that's important or not right now, but it's bugging me a bit.

S7, the wait for answer timer. That has to be it! I don't know how I missed that. I'm going to try it right now.

Yep, that was exactly what it was. S7 was set for one second. I still don't know how that happened, but who cares? It's working and I'm happy.

Thanks a million for your help everyone!

Very cool! I wouldn't have seen it unless you did the profile dump.

And I've got to hand it to sph, he was on top of the ATS86? query long before I was. Some modems are commanded by ATV0 or ATV1...others via the s86 register. What can I tell 'ya? I was impressed, so I gave him a rating.

The thing about the X1 parameter makes sense, especially if you're using a Lucent Technologies LT Win (Agere) modem. That modem in particular has a habit of detecting dialtone when conversation is on the line, which it proclaims after sensing a ½ second of audio energy on the line--regardless of the frequency or cadence.

Wow... I didn't think this would ever be figured out.... It does go to show that there is a great deal of arcane knowledge here, and it will be completely lost on the next generation....

I totally agree! :bow:

What a major learning experience this has been to follow this epic along. It just goes to show what a high level of knowledge there is here and the commitment to help one another across the country.

Mentors are you all, thanks for the lesson.

aww, i'm all bummed i missed this one... i did modem tech support back in the 90's until Dennis Hayes bought the company (after Paul Allen got done raping & pillaging us!).