Maxim Integrated Teridian V.22 bis Linux Softmodem for 73M1822/73M1922 MicroDAA - Manual (Page 64)

V.22 bis Linux Softmodem for 73M1x22 MicroDAA User Guide UG_1x22_043
64 Rev. 1.5
SMS Applications continued
18. Turn on RTS (to switch TSC Softmodem modem to transmit mode)
19. Wait for CTS on
20. Transmit DLL_SMS_ENQ message if the ACK1 was a null message or next
DLL_SMS_INFO_MO to send another data frame
21. Turn off RTS (to switch modem to receive mode)
22. Wait for DCD on
23. Detect DLL_SMS_ACK1 again from SM-SC if the ACK1 was a null last time or
DLL_SMS_ACK0 for the SMS_INFO_MO frame just received.
24. (Assuming DLL_SMS_ACK0 was received above) Wait per SMS timing and DCD
turn off (SM-SC switched to receive mode)
25. Turn on RTS (to switch TSC Softmodem modem to transmit mode)
26. Wait for CTS on
27. Transmit DLL_SMS_REL message to end session
28. Turn off RTS (to switch TSC Softmodem modem to receive mode)
29. Wait for DCD on
30. Detect DLL_SMS_ACK1 message from SM-SC acknowledging the end of the
session.
END
Case 2: SM-SC to TE transmission of a SMS
1. Set the Local Host serial data rate to 1200bps
2. The Local Host controls the V23 carrier with RTS signal
3. Turn off RTS (to prevent sending carrier too early)
4. ATY0B10C2S73-32S10=255S0=2 (Auto answer on 2 rings)
5. Modem auto answer SMS-SC call after S0 rings
6. Modem will display "Connect 1200" with CTS off and DCD off
7. Turn on RTS (to switch modem to transmit mode)
8. Wait for CTS on
9. Prepare to send the DLL_SMS_EST signal from the SM-TE. From the Local Host
send the “+++ATS60=3” escape sequence to modem to switch to the on-line
command mode along with the ATS60=3 command to set the modem to transmit
alternating 0/1s
10. Wait for 240 ms and then the ATO command to turn off the alternating pattern and
start to transmit a MARK signal for 70ms.
11. Turn off RTS (to switch TSC Softmodem modem to receive mode)
12. After completion of the Channel Seizure & MARK signal transmission, from the
Local Host send ATS60=0O to return to the data mode
13. Wait for DCD on
14. Receive DLL_SMS_INFO_MT message from SM-SC (SM message information)
There may be multiple messages and ACKn’s if segmented messages are sent.