| ??? 05/11/05 01:14 Modified: 05/11/05 01:18 Read: times |
#93284 - Protocol analyzer Responding to: ???'s previous message |
Mahmood Elnasser said:
Dear Nahid
What might be very helpful, since you managed to make microcontroller communicate with PC is build a modem simulator program on the PC, which responds to all your AT commands used before you actually connect the modem. This way things will be much easier for you to debug and understand whats going on. Once this has been successful then the microcontroller should connect directly to the modem. Regards Mahmood Beyond Logic's freeware RS-232 Protocol Analyser is immensely useful for this kind of work; being able to see bytes go back and forth on the wire really speeds up debugging. I used this recently when developing a serial protocol for an 8051 <-> PC application. It's not a perfect solution; there were some synchronization problems (probably due to my PC), but it helped me quickly find some problems that would have taken a very long time to diagnose otherwise, such as the fact that Windows sent me a large number of bytes following the 8051's XOFF transmission before actually pausing. The protocol analyzer works as something of a passive observer on your RS-232 link; neither of the endpoints need be PCs in order to use it, making it perfect for debugging an 8051 <-> modem link. --Sasha Jevtic |
