Using a Serial Connection Not being able to download data from your particle counter over a serial connection usually has one of two root causes. 1. The Cable is broken or damaged To trouble shoot this inspect both ends of the cable for any sign of bent pins abnormal wear or cuts If the cable looks good continue to step two 2. Download the correct drivers for serial If you have a computer you have never downloaded data with you may need to download  appropriate the drivers which can be found HERE . If you still cannot connect to your instrument Feel free to contact tech support by either sumbitting a tech support form or using the live chat function on the bottom right of your browser.