SDAA112 September   2025 AM625

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Use Case
  5. 2Platform and Products
    1. 2.1 Hardware
    2. 2.2 Software
  6. 3Methods
  7. 4Overview of Steps to Bring Up the Interface and Establish A Connection
  8. 5Troubleshooting
    1. 5.1 Power and Initialization First
    2. 5.2 Verify Network Before PPP
    3. 5.3 Test Manual Dial First
    4. 5.4 Timing When Dialing Up
    5. 5.5 Serial Communication
    6. 5.6 Chat Script
    7. 5.7 PPP Options
    8. 5.8 Signal Strength and Antenna Setup
    9. 5.9 Modem Reset
  9. 6Summary
  10. 7References

5.6 Chat Script

In the peer file, the line

connect "/usr/sbin/chat -v -f /etc/ppp/peers/bg95-chat"

handles dialing and Packet Data Protocol (PDP) setup. If the AT commands fail, inspect the chat script closely for formatting issues.

For debugging, enable ECHO ON in the script, or run chat manually with the command below to watch the exchange without involving pppd.

chat -v -f script > /dev/ttyS0 < /dev/ttyS0

Note that stray or invisible characters in chat scripts can cause unexpected failures. Always edit in a plain text editor using UNIX line endings. Aborting conditions are strict: any matching abort string immediately stops the script. During experimentation, consider commenting out aborts to avoid premature exits.