thanks for replying. i succeeded with downloading my python script and now its working fine. but also some have some problem. first “at#sgact” command doesnt works and instead i’m using “at#sktd” and its wokring. although i prefer “at#sgact” and “at#sd” . of course these are working correctly by at command control from pc. and next prblem is my python script works whether dtr is high or low. of course i configured at#startmodescr.