Modem management
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Posted By:   Arun_Vadlamani
Posted On:   Wednesday, September 18, 2002 03:21 PM

I am using the java comm API to do the following, - read/write to a serial port - the modem attached to the serial port dials and talks to another modem and gets back response. - Need to maintain the communication to complete the protocol transfer. I am getting different results everytime I dial the modem - Good response - The other modem sees some junk characters which I am not sending, this results in a disconnect as the junk characters are not part of the protocol. Can someone help me with the following - How can I suppress any modem (the modem on my serial port) related feedback to the    More>>

I am using the java comm API to do the following,

- read/write to a serial port

- the modem attached to the serial port dials and
talks to another modem and gets back response.

- Need to maintain the communication to complete the
protocol transfer.

I am getting different results everytime I dial the modem

- Good response

- The other modem sees some junk characters which I am
not sending, this results in a disconnect as the junk
characters are not part of the protocol.

Can someone help me with the following

- How can I suppress any modem (the modem on my serial port)
related feedback to the port. (I am already sending
ATQ1 - does not help much)

- Is there a way to overwrite the content on the serial port
so that I only have the responses from the other modem
when I read the port.

- If anyone has done some modem communication using JAVA
can you please send me some suggestion or sample code.



Thanks in advance.

Arun

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Re: Modem management

Posted By:   Jorgen_Nordqvist  
Posted On:   Wednesday, September 18, 2002 07:37 PM

ATQ1 should inhibit result codes to the DTE, unless the junk characters you see is a result of spurious (noise?) signals on the modem line or if the baud rate has fallen out of synch. Try disabling modem fallback with AT%E0.

It might pay to hook up Hyperterminal or something similar on the other side just so that you can see what kind of data is coming through. That way you can also rule out your Java app/API having any influence on the data you see coming through.

Jorgen

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