Problems with modems and AT commands

Hello, everyone
I have USB EDGE modem. In System Preferences > Network I see this device as "CDC device". I have entered all Settings, but I can't connect to the internet. MACOS says: "A crossed connection has been detected. Please verify your settings and try again".
I found the problem, but I can't solve it.
I'm working with terminal/AT commands and writing modem scripts (CCL) by myself. When I enter the command "ATD*99#" modem should connect and give me an answer "CONNECT". But after that command there is no answer and modem is not responding. I should reattach the modem to USB port. The same problem with command "ATD 99**1#".
I have tried third party tool to enter these commands - same problem too.
In PC, Windows OS it's OK. After "ATD*99#" command, modem says "CONNECT". Then I can communicate.
By the way, other modem (USB GPRS) is working good in MACOS. I enter "ATD*99#" and it says "CONNECT". Than MACOS connects to internet.
I think the problem is because my EGDE modem is CDC device, and my GPRS modem is as Virtual COM Port.
Maybe, MACOS blocks my command (ATD*99#), which I',m trying to send to CDC device?
One more interesting thing: when I'm trying to send command "ATZ" to CDC device - I have the same problem...
Maybe someone can explain me this? Thanks for help.

iBook G4, Mac OS X (10.4.11)

Posted on Dec 12, 2008 4:34 AM

Reply
15 replies

Dec 14, 2008 11:50 PM in response to BDAqua

BDAqua wrote:
Hi Gvidas, and a warm welcome to the forums! 🙂

Is it listed as a Serial device or an Ethernet device?

See if this helps...

http://www.tigoe.net/pcomp/resources/archives/avr/000749.shtml

Or maybe try ZTerm...

http://homepage.mac.com/dalverson/zterm/

Hi, BDAqua 🙂

It is listed as USB modem, as it is: /dev/tty.usbmodem3B11
I'm working with device as Serial device. I have tried "screen", "goSerial", "zTerm".
In all these programs the same problem: modem is not accepting ATD*99#, ATD 99**1# or ATZ and then stops responding.

How I do it:
1. I have option selected "Connect using a terminal window (command line)"
2. I'm pressing the button "Connect". Then I have terminal window
3. I'm sending to modem initialization string: AT&FE0V1&C1&D2S0=0. Modem says: OK
4. I'm starting data call: ATD*99#
After this, looks like I didn't press the return key. But I did. I can not enter any symbols to terminal and modem is not responding. Even if I'm trying to restart terminal, I can't enter any symbol.

It's not modem problem - on PC Windows HyperTerminal it works perfect - after ATD*99# I have "CONNECT".

Dec 14, 2008 11:58 PM in response to John Galt

John Galt wrote:
I believe it should be ATDT then the number.

Only if you're using DTMF dialing. I believe ATD will default to pulse dialing.

It's conceivable the OP's location in Lithuania might not support touch-tone.

For voice calls OP's in Lithuania supports both modes. I can call to my cellphone in 3 ways:
ATDT my_number_here;
ATDP my_number_here;
ATD my_number_here;

When I'm starting data call to my cellphone:
ATDT my_number_here
ATDP my_number_here
ATD my_number_here
Modem says: "NO CARRIER"

After ATDT*99# modem says:
ERROR

After ATDP*99# modem says:

+CUSD: 0,"UNKNOWN APPLICATION",15

OK

But it's not important, because ATD*99# is ok for this modem, because it _works good on PC_.

Who can tell me, why MACOS is not accepting ATD*99# and few other AT's? Or maybe MACOS interprets it wrong?

Dec 15, 2008 1:20 AM in response to Gvidas

How I do it:
1. I have option selected "Connect using a terminal window (command line)"
2. I'm pressing the button "Connect". Then I have terminal window
3. I'm sending to modem initialization string: AT&FE0V1&C1&D2S0=0. Modem says: OK
4. I'm starting data call: ATD*99#

Sorry, I forgot to write one more step between 3 and 4:
I'm entering connection info by AT+CGDCONT=1,"IP","banga"
("banga" is my APN).

So, I'm continuing my work with that problem. Today I found one more unfriendly AT:
AT+CGDATA="PPP",1
After that, modem also stops responding. It looks like, MACOS is filtering my AT commands and doing something with them...

Dec 15, 2008 3:26 AM in response to BDAqua

BDAqua wrote:
It looks like, MACOS is filtering my AT commands and doing something with them...


Hmmm, I think you must be on the trail, I did read something about CDC devices needing Serial commands converted to something or other, but can't find it now.

Anyway you can "capture" the actual output from the PC?


Yeah, I'm searching about that, but cant't find it too.

So, on PC:
AT+CGDCONT=1,"IP","banga"
OK
AT+CGDCONT?
+CGDCONT: 1,"IP","banga","0.0.0.0",0,0

OK
ATD*99#
CONNECT

It's connected, as you see.

Then on iBook:
AT+CGDCONT=1,"IP","banga"

OK
AT+CGDCONT?

+CGDCONT: 1,"IP","banga","0.0.0.0",0,0

OK
ATD*99# <-- nothing happening, my cursor doesn't move to new line</div>
If I'm pressing Continue after that, my Connection Log:
Mon Dec 15 13:17:28 2008 : Serial connection established.
Mon Dec 15 13:18:32 2008 : Terminal connection established.
Mon Dec 15 13:18:32 2008 : using link 0
Mon Dec 15 13:18:32 2008 : Using interface ppp0
Mon Dec 15 13:18:32 2008 : Connect: ppp0 <--> /dev/**.usbmodem3B11
Mon Dec 15 13:18:34 2008 : sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0xe9fd042c> <pcomp> <accomp>]
Mon Dec 15 13:18:37 2008 : sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0xe9fd042c> <pcomp> <accomp>]
Mon Dec 15 13:18:40 2008 : sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0xe9fd042c> <pcomp> <accomp>]
Mon Dec 15 13:18:43 2008 : sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0xe9fd042c> <pcomp> <accomp>]
Mon Dec 15 13:18:46 2008 : sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0xe9fd042c> <pcomp> <accomp>]
Mon Dec 15 13:18:49 2008 : sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0xe9fd042c> <pcomp> <accomp>]
Mon Dec 15 13:18:52 2008 : sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0xe9fd042c> <pcomp> <accomp>]
Mon Dec 15 13:18:55 2008 : sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0xe9fd042c> <pcomp> <accomp>]
Mon Dec 15 13:18:58 2008 : sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0xe9fd042c> <pcomp> <accomp>]
Mon Dec 15 13:19:01 2008 : sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0xe9fd042c> <pcomp> <accomp>]
Mon Dec 15 13:19:04 2008 : LCP: timeout sending Config-Requests

Dec 29, 2008 12:08 AM in response to BDAqua

BDAqua wrote:
I wonder if there are some clues here for you...

http://wiki.openmoko.org/wiki/MacOS_X

They do mention OSX/CDC Drivers...

http://wiki.openmoko.org/wiki/MacOSX#Apple_CDC_Ethernet_driver10.4.10


Thank You, but these drivers are not helpfull for me, or I do something wrong.
After installing this, there is no my modem port in /dev anymore. Before installing these drivers, there was:
/dev/tty.usbmodem3B11
/dev/**.usbmodem3B11


I searching so much in the internet and I think, problem is because of 2 modem interfaces. There are:
1) Interface #0 - Communications-Control
2) Interface #1 - Communications-Data/Unknown Comm Class Model

I'm using USB Prober. So there is my IORegistry output for that device:

|usb@1B,1 <class IOPCIDevice>
|....AppleUSBOHCI <class AppleUSBOHCI>
|........OHCI Root Hub Simulation@1B,1 <class IOUSBRootHubDevice>
|............AppleUSBHub <class AppleUSBHub>
|............IOUSBInterface@0 <class IOUSBInterface>
|........Teltonika CDC device@3b100000 <class IOUSBDevice>
|............AppleUSBCDC <class AppleUSBCDC>
|............control ifac (ACM AT)@0 <class IOUSBInterface>
|............data ifac@1 <class IOUSBInterface>
|................AppleUSBCDCACMData <class AppleUSBCDCACMData>
|....................IOModemSerialStreamSync <class IOModemSerialStreamSync>
|........................IOSerialBSDClient <class IOSerialBSDClient>

After installation of drivers ( http://wiki.openmoko.org/wiki/MacOSX#Apple_CDC_Ethernet_driver10.4.10), there are no these lines anymore:

|................AppleUSBCDCACMData <class AppleUSBCDCACMData>
|....................IOModemSerialStreamSync <class IOModemSerialStreamSync>
|........................IOSerialBSDClient <class IOSerialBSDClient>

Can somebody explain me, what I need and how to restore/repair Apple Original CDC driver? I want to work with my modem, as with Virtual Serial Port. I think, I need both interfaces for this, right?

Dec 30, 2008 6:16 AM in response to BDAqua

BDAqua wrote:
I don't know if reinstalling the big 10.4.11 Combo update would do it, or an Archive & Install, or using Pacifist to extract some PKG from te install disk, but one at least should work.


Yes, I found a good solution somewhere:

$ sudo -s
# mkdir /kexts.orig
# mv /System/Library/Extensions/IOUSBFamily.kext/Contents/PlugIns/AppleUSBCDC* /kexts.orig
# cd /
# pax -r -z -f /Volumes/Mac\ OS\ X\ Install\ DVD/System/Installation/Packages/Essentials.pkg/Contents/Archive.pax.gz *AppleUSBCDC *


Now see my /dev/tty.usbmodem3B11 again:)
So I'm starting again... Now I know, my problem is because of drivers and two modem interfaces. So, I'm closing this post. I'll make another post with most detailed information about my problem and modem information in Peripherals section.

Thanks for help!

This thread has been closed by the system or the community team. You may vote for any posts you find helpful, or search the Community for additional answers.

Problems with modems and AT commands

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