Simulate analog and digital function blocks
                    What is full form of FBD?
                  
                  
                  
                
                  
                    DCS was evolved from
                  
                  
                  
                
                  
                    What is the output of OR block if any one of the input is high or active or true?
                  
                  
                  
                
                  
                    What is the output of AND block if any one of the input is high or active or true?
                  
                  
                  
                
                  
                    Production level control is _____ level in hierarchical distributed structure