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kumar
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India		Posted - 4/26/2004 4:39:53 AM  Show Profile  Email Poster  Edit Message
I am using a hayes optima 386 modem to connect to some devices. I am using AT commands for connecting. Some times when i use the command "ATDT xxxx" to connect modem responds with a "OK" instead of the usual "CONNECT"/"NO DIALTONE"/"BUSY"/"NOCARRIER".

Any help on this would be greatly appreciated.

Thanks in advacne

kumar

v.Richard
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USA		Posted - 4/30/2004 2:01:19 PM  Show Profile  Email Poster  Edit Message  v.Richards Homepage
If there is a semi-colon in the dial string, the modem will remain in command mode and respond with OK.

ATD345;

Aloha! Richard.

kumar
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India		Posted - 5/5/2004 2:13:08 AM  Show Profile  Email Poster  Edit Message
Their is not semi-colon in the dial string
kumar
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India		Posted - 5/5/2004 2:13:37 AM  Show Profile  Email Poster  Edit Message
Richard,
Their is no semi-colon in the dial string

kumar

v.Richard
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USA		Posted - 5/5/2004 10:44:31 AM  Show Profile  Email Poster  Edit Message  v.Richards Homepage
What software are you using to make the connections?

Your modem might also respond with OK after being given a dialing string if there is an extra carriage return or any extra character sent to the modem after the carriage return.
Suggest you check behavior of modem by testing with Hyperterminal connected to modem com port as described at
www.modemsite.com/56k/x2-hyperterm.asp
and give modem dial command, enter, then before carrier is obtained, press a key, return, etc. and see what modem responds.

Aloha! Richard.

kumar
Tl Posts:
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India		Posted - 5/7/2004 12:51:43 AM  Show Profile  Email Poster  Edit Message
Richard,
Their is not additional carriage return. No additional character is sent with the dial string.

I am initializing the modem just before dialing (maximum time between initialization and dialing is 1 second). It is so happenning that i am receiving "OK" twice for the initialization. Now my problem seems to have been resolved after i did the following steps:
1. Introduce some delay between initialization and dialing.
2. Purge the serial port using PurgeComm(...) before writing ATDTxxxx.
Any thoughts as to why the modem is sending OK twice. Also as i mentioned earlier this is not a consistent problem.

pramod

kumar
Tl Posts:
5

India		Posted - 5/7/2004 12:51:54 AM  Show Profile  Email Poster  Edit Message
Richard,
Their is not additional carriage return. No additional character is sent with the dial string.

I am initializing the modem just before dialing (maximum time between initialization and dialing is 1 second). It is so happenning that i am receiving "OK" twice for the initialization. Now my problem seems to have been resolved after i did the following steps:
1. Introduce some delay between initialization and dialing.
2. Purge the serial port using PurgeComm(...) before writing ATDTxxxx.
Any thoughts as to why the modem is sending OK twice. Also as i mentioned earlier this is not a consistent problem.

pramod

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