How do you view or log modem string?

[R32]

Have some external modems I use at work. These are Supra288 Express modems. Would like to know if there is a way to view what current string is on these modems? Modems are set to Auto answer to a piece remote equipment.

I do have other modem strings to use if needed but these current modems have custom strings written by someone previous to me. These modems work flawless compared to the modem strings recommended by the manufacturer. I think theses custom strings were written to compensate for communication problems between the remote machines and the modem being used.

I've read in some other threads of modem diagnostic commands to troublshoot modem problems. Is there a command used to view what current string is on modem?

Would it be possible to connect a laptop between modem and remote machine via; serial comm ports to capture string usage? Thanks

 

[pansophic]

Because these are external modems you have a lot of options. If you are comfortable making cables, then you can create a "Y" cable and plug that into a laptop and capture the init strings as they are sent. Make sure that you only connect the TD and Signal Ground to the laptop, as the control leads may interfere if they are connected. Oh, and the TD from the computer gets connected to RD on your laptop. You can only monitor one side of the connection this way unless you have 2 COM ports on your laptop.

However, it is probably easier to run Hyperterminal (or a better terminal emulator) configured to direct connect to COM 1. Then you just plug the laptop into the modem directly and issue the following commands:

AT&V<cr>
ATI4<cr>

One of the two commands should show you all of the pertinent configuration data without modifying the configuration of the modems.
pansophic

 

[R32]

I tried this out on my desktop to see what response I would receive. I pulled up the modem log on my desktop and compared it to the responses I received in Hyperterminal. The strings do not look the same. Why would the be? Or am I missing something when comparing the two?

Below is a copy of my Hyperterminal session and Modem log to compare.

Hyperterminal:

STORED PROFILE 0:
B1 E1 L1 M1 N1 Q0 T V1 W0 X4 Y0 &C1 &D2 &G0 &J0 &K3 &Q5 &R1 &S0 &T5 &X0
S00:000 S02:043 S06:002 S07:050 S08:002 S09:006 S10:014 S11:095 S12:050 S18:000
S36:007 S37:000 S40:104 S41:195 S46:138 S95:000

STORED PROFILE 1:
B1 E1 L1 M1 N1 Q0 T V1 W0 X4 Y0 &C1 &D2 &G0 &J0 &K3 &Q5 &R1 &S0 &T5 &X0
S00:000 S02:043 S06:002 S07:050 S08:002 S09:006 S10:014 S11:095 S12:050 S18:000
S36:007 S37:000 S40:168 S41:195 S46:138 S95:000

TELEPHONE NUMBERS:
0= 1=
2= 3=

OK
ATI4
a007880284C6002F

bC60000000

r1005111151012004

r3000111170000000

OK

Modem Log:

11-2003 15:01:26.11 - Hayes 56K Int Data+Fax in use.
02-11-2003 15:01:26.13 - Modem type: Hayes 56K Int Data+Fax
02-11-2003 15:01:26.13 - Modem inf path: HAYESM~2.INF
02-11-2003 15:01:26.13 - Modem inf section: Modem1
02-11-2003 15:01:26.40 - 115200,N,8,1
02-11-2003 15:01:26.41 - 115200,N,8,1
02-11-2003 15:01:26.41 - Initializing modem.
02-11-2003 15:01:26.41 - Send: AT<cr>
02-11-2003 15:01:26.42 - Recv: AT<cr>
02-11-2003 15:01:26.42 - Recv: <cr><lf>OK<cr><lf>
02-11-2003 15:01:26.42 - Interpreted response: Ok
02-11-2003 15:01:26.42 - Send: AT&F E0 V1 &C1 &D2 S95=47<cr>
02-11-2003 15:01:26.42 - Recv: AT&F E0 V1 &C1 &D2 S95=47<cr>
02-11-2003 15:01:26.43 - Recv: <cr><lf>OK<cr><lf>
02-11-2003 15:01:26.43 - Interpreted response: Ok
02-11-2003 15:01:26.43 - Send: ATS7=60S30=0L1M1&Q5S46=138&K3B0N1X4<cr>
02-11-2003 15:01:26.44 - Recv: <cr><lf>OK<cr><lf>
02-11-2003 15:01:26.44 - Interpreted response: Ok
02-11-2003 15:01:26.45 - Dialing.
02-11-2003 15:01:26.45 - Send: ATDT;<cr>
02-11-2003 15:01:28.26 - Recv: <cr><lf>OK<cr><lf>
02-11-2003 15:01:28.26 - Interpreted response: Ok
02-11-2003 15:01:28.35 - Dialing.
02-11-2003 15:01:28.35 - Send: ATDT##########<cr>
02-11-2003 15:01:56.97 - Recv: <cr><lf>CARRIER 42000<cr><lf>
02-11-2003 15:01:56.97 - Interpreted response: Informative
02-11-2003 15:01:57.26 - Recv: <cr><lf>PROTOCOL: LAP-M<cr><lf>
02-11-2003 15:01:57.26 - Interpreted response: Informative
02-11-2003 15:01:57.26 - Recv: <cr><lf>COMPRESSION: V.42BIS<cr><lf>
02-11-2003 15:01:57.26 - Interpreted response: Informative
02-11-2003 15:01:57.26 - Recv: <cr><lf>CONNECT 42000/ARQ<cr><lf>
02-11-2003 15:01:57.26 - Interpreted response: Connect
02-11-2003 15:01:57.26 - Connection established at 42000bps.
02-11-2003 15:01:57.26 - Error-control on.
02-11-2003 15:01:57.26 - Data compression on.
02-11-2003 18:26:59.91 - Hanging up the modem.
02-11-2003 18:26:59.91 - Hardware hangup by lowering DTR.
02-11-2003 18:27:02.15 - Send: ATH<cr>
02-11-2003 18:27:02.64 - Recv: <cr><lf>OK<cr><lf>
02-11-2003 18:27:02.64 - Interpreted response: Ok
02-11-2003 18:27:02.64 - 115200,N,8,1
02-11-2003 18:27:02.67 - Session Statistics:
02-11-2003 18:27:02.67 - Reads : 4383626 bytes
02-11-2003 18:27:02.67 - Writes: 1423202 bytes
02-11-2003 18:27:02.67 - Hayes 56K Int Data+Fax closed.



R32

 

[pansophic]

The differences are pretty minor, but my first guess as to why they are different would be that you opened the Modem in Hyperterminal, not the COM port. If you open the Modem with Hyperterminal, TAPI will initialize the COM port with the stored parameters. If you open a COM port directly, TAPI will not initialize the port (because it doesn't know if there is a modem there or not).

In the case of your external modems, if they are initialized by the application that you are using, and you disconnect the cable and attach it to another computer, the configuration will not change. If you are using a terminal emulator attached directly to the COM port, then you will not initialize the modem.

Unfortunately, there are many parameters that don't show up on the AT&V query. To get the full configuration, you'd have to query each S register individually. It is not difficult, but it is time consuming and error prone.

You may be better off building the &quot;Y&quot; cable and just catching the initialization commands as they come off the application.
pansophic