sundance-communications.com/forum Forums TDM Business Telephone Systems Comdial Telephones & Systems DX120 modem string

We have a customer who has a DX120 with 4 port VM. The system has been rock solid for 3 years now, but about twice a year, they need some changes in the VM or system programming.


We've always just gone out there for a service call, because it involved some wire work at the MDF.
This week I tried to get into their system remotely and couldn't. I've been in before but always had a problem. Here's what happens:

I dial in at night---the AA answers after 5 rings (I put in a bunch of commas), I get modem tone, I get handshake sometimes and then it seems as if my external modem disconnects---or it may be the DX120s modem--I'm not sure.

Does the digit string need to be changed for this customer because of the long time before it answers? I use AT&fe0Q0v1&c1s7=255 on all of my customers---but their AA answers after 1 ring.

If it does need to be changed---what do I change??

I spent the afternoon checking out modem strings & AT commands and modem troubleshooting. I may have found the answer. Later tonight I'll try some tests to see if changing the AT commands a bit helps.

Are you talking about using the on board modem of the 7270c?

Yes. Using PCDBA, there is a window that you can change the modem string---it's the same on all of my customer files---but in the 120 manual---you can see that they have a picture of different strings. I'm pretty sure that the modem string sets MY PC's modem.

I think that for this one customer, my modem is disconnecting (due to a time out or it's not seeing something in a certain time) and I'm trying to figure out if I can change something to correct this.

There are S registers, and other commands that might adjust this timing (or whatever). I just don't know what works and what doesn't because I have never changed anything in that window before---because all of my other customers---the AA answers immediately or in one ring.

I got into this customers DX120 Friday afternoon by calling in and having the receptionist transfer me to the modem---that eliminated the 5 or 6 rings. So the DX120 modem is fine and my modem is fine---it's just the "timing" I think--is off.

Put your butt set in line with your modem. Uncheck "Detect dial tone before dialing" in your modem settings. Put 100 in your modem dial string--Dial with the butt set-when you hear AA hit dial on the laptop then hang up on butt set.

Well, I must say, that this tip came in really handy tonight.

I came across another customer who had 9 rings in night mode before the AA answered---so I did what you said---and it worked perfectly. In looking at what you suggested, I guess I should have figured that out---but I would have never guessed that the "Detect dial tone before dialing" window was the key. It all makes sense, now.

Thanks, AWeaver.......!!!

Mick, I've been using ATE1Q0X1S11=200S7=90S8=13

X1 means that my modem ignores the presence of dial tone, call progress tones, busy signals, etc.

S11=200 sends longer DTMF tones for AAs to "hear"

S7=90 gives me 90 seconds for the far-end modem to connect before timing out.

S8=13 means that one comma gives me a 13 second pause.

This works well so that I can put in a phone number followed by one comma, then the remaining digits.

If I remember we used to insert ^ in the string somewere to send modem tone to the far end modem, so that it would shake hands.

Ed & Jim---I'm going to try those this week some time.
Thanks for the tips!!