Posted 29 Feb 2016 I am doing a data collection from OMRON PLC CP1L through MS excel VBA use API function. The connection was setuped correct (I think)both in PLC and PC side. The trick things is when PLC have USB cable connected the data was send to PLC and can get feedback through RS232 in normal.(I use portmon moniter the progress,and I can see the data (C-command ).But when I get the USB cable removed ,The PLC can not get any reponse back.Dose any of you have met that before? Share this post Link to post Share on other sites
