System FaX Flow_and_Issues?
We have been through some issues with integration of FAX Relay into TTMS320C55XX. The Object code for the FAX relay was from a TI Third Party vendor, who lacks in support after the SALE.
Attached is a situation we are into and are unable to integrate.
1) When do we switch from voice to fax mode for t.38 fax. Any handshaking process to be followed?
2) Please guide us through the API's used in initialization and processing. Also share any case study for fax integration with example code.
Fax Process Implementation Flow
Following is our system block diagram followed with the code flow chart with respect to our system
Fig1-System Block Diagram
Flow chart of the Application Code for fax
START
FAX Machine A is in Dial mode
10 digits are dialed
Code Enters the Fax Mode (Fax processing) with 14400 baud rate set Inside the fax processing part the PCM data which is received from Audio codec through one of the MCBSP (MCBSP0) is taken and passed on to API functions of Fax relay processing For every 10 ms new PCM data will come from the audio codec which is scheduled in DSP BIOS (software event) the same process will continue until the data is received B
The Relay processed data is transmitted through another MCBSP (MCBSP1) (originating Fax) to other DSP (Terminating Fax) Voice codec (G723.1A) will establish call and CED, CNG signals will be exchanged in voice mode at 6300 baud rate Voice to fax bit is enabled to fax mode after approximately 40 seconds (approx. after CED is obtained) to switch from voice to Fax mode and control moves to fax processing part to send fax Do we need to dial in voice mode and after CED CNG signals are exchanged between two fax machines after that do we need to switch to T.38 mode (fax mode) for further processing and send fax?
At present in our system we can see that in voice mode under baudrate 6300(voice codec (G723.1)) the following behavior when dialed 10 digits and pressed fax start button
1. Dial 10 digits from the transmit fax machine and press start button
2. Ring will appear on the receiving fax machine and CED, CNG signals will be exchanged between two fax machines
3. Transmitting fax machine will display “Sending page”
4. At receiving fax “Receiving page” will appear
5. Within some seconds transmit side fax displays “Transmit error” message
Based on the above behavior can you tell what could be issue?
ANY HELP, is appreciated. contact
sales@linkstartechnology.com
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