dump using serial

[niños69]

guys i haave been tring to dump cgn3 moddem using serial but no luck.
can anyone guide me how this can be done please.
i manage to connect through putty but i dont know how to save the bin here is a out put from putty

Root FS size ............. 0x71b400
Additional FS ............
========== Script Done ============================

*** UBFI1 bootscript executed successfully.
Start booting...
## Booting image at 03c58338 ...
ARM MBX sending 'eMMC done.' notification...
Image Name: Multi Image File
Image Type: ARM Linux Multi-File Image (uncompressed)
Data Size: 8585352 Bytes = 8.2 MB
Load Address: 00a00000
Entry Point: 00a00000
Contents:
Image 0: 1133692 Bytes = 1.1 MB
Image 1: 7451648 Bytes = 7.1 MB
OK

Starting kernel ...

Starting LZMA Uncompression Algorithm.
Compressed file is LZMA format.
[Debug - Kerenl] LZMA Uncompression - Done.

thanks