we are using automation system for maintaining the room temperature by using vb software tool. we are using digi connect port x4 and xs-z6-cb2r digi sensors and ethernet connection. it is a continuously monitoring system and stored in database. here some sensors are go to zero level and automatically comes to present level after in variable time intervals. time interval is not same for each time and also going to zero state also different time interval. we cant able to backup the data of previous session (which time of sensors in zero level). some time our software page going inactive (some pop up screens will arrives ).some time non of data are stored in database in some times. after data are stored after reopen the app from first or restart the system only.