There have been several firmware improvements in regards to modem connections and Challenger10, It is recommended you have the current firmware to avoid potential issues.
Menu 19-9-2 Create a new path or modify existing (Path 10 is default)
1, Path Main
*Account Number will be the Challenger number created in titan
2, Connection Control
* Ensure "always connect" is NOT ticked
* Enable "stay connected on Empty buffer"
* Enable "Command Control"
5, Dial Settings
* YES "auto answer"
* Rings and calls setup
6, Advanced Settings
Computer Attempts: 256
Message Retries: 3
Timeout on Message ACK: 200
Reconnection Timeout: 5
Challenger10 now ready to connect modem
When setting up PORT in Titan make sure you set the baud rate at 57600.
If using a Hills supplied modem use strings ATZB0 or AT=MS=9,0,1200,4800
It has also been noted in some cases to try the connection with no strings set at all.
Should further issues remain:
* if Comms path is not path 10, then DTMF should be set to ON
* Check the voltage on the phone line should be 48-52V