When I connect to my inverter to Modbus then one pop-up show Modbus Exception Response from Slave Device. No. of polls increases but valid slave response still 0. Various reading is displayed on the screen. What is the problem going on?
There is a page set up where you can check all the exceptions thrown by the Modbus and their solving. I recommend you access the page through the Google's Cache feature since it appears that the domain where the page was hosted is no longer working.
Google's Cache makes it easier to access pages that are temporary out of order or discontinued. Sometimes you can even download apps.
Here is the link: http://webcache.googleusercontent.com/search?q=cache:9evAonTz2BsJ:www.simplymodbus.ca/exceptions.htm+&cd=1&hl=ro&ct=clnk&gl=us