Products In This Thread

LTC4331 Production
The LTC4331 is a point-to-point SMBus compatible I2C slave device extender designed for operation in high noise industrial environments. Using a ±60V fault...
Datasheet
LTC4331 on Analog.com

  • State Verified Answer
  • Replies 2 replies
  • Subscribers 32 subscribers
  • Views 569 views
  • Users 0 members are here
Options
Related 

        

            Post
             Go back to editing
        

    

    


    

    









		












	
	
			
	
			
		
	
	
		

		
LTC4331, remote I2C interface doesn't respond



		

			

									
					    wblo
					
							

			
				
									
											
			
			
				
    
			
			
			    	
			                    
                
				                on Aug 24, 2021 
				
			
			
		
    

				
		
    
		    		    
		    
		    	
			
    Hi,
    

    I'm experimenting with the LTC4331 demo board, with my own uproc board. My setup is:
    

    uproc <===> local LTC4331 <===> cable <===> remote LTC4331 <===> EEPROM
    

    program is simple: continuously reading from (remote) EEPROM, filled with know data. So after each read do a compare, etc.
    

    Initially I had spurious issues of stuck SCL, but found this article: Unexpected behavior of LTC4331 - Q&A - Interface and Isolation - EngineerZone (analog.com)
    After delaying each read with at least 35ms, as suggested in the article, all went fine.
    

    Now next step I want to experiment with the control interface of the device. I can read the local I2C device (address 0x3E), but I get NAK's from the remote device. I tried every jumper setting for A1/A2, even made a quick scan routine to find all I2C devices. But all what is reported is 0x3E and 0x50 (for the remote EEPROM).
    

    Q1: Is the remote I2C device suppose to respond on I2C register access?
    Q2: Is the Packet Error Correction also applicable for the data transfer from my remote EEPROM to the local LTC4331? Or is PEC only used for transfers from uproc to the LTC4331 control interface?
    Q3: related to Q2, if any bit error occurs in the transfer from reading my remote EEPROM to the local LTC4331, will that be detected as a 'fault'?
    

    regards,
    _Wim_
    
									
			        
		
    

				
						
        

    
    Tags: 
                                            
                 interface and isolation
                
                                                    
                 LTC4331
                
                                                    
                 Serial Bus Buffers  Extenders  and Accelerators
                
                                
            
    
    
    

		
    
			
						
									
									
						
						
			
			
			
			
		
    

        
        

					
    
			
    


    


	















    
	
    
	
    
					



			








	
	
	
	



Parents
	
      
	

    • 
	
      



	
			
		
	



      
	
      
		
      
							
					
      
		
      
			
													0
							
			
				
									
							        
			
			
			
      •  Analog Employees  
      
            
			                            
                                                                                                                        
            
				
			
            
					
      
	
      

		
		
      
					
      The control interface is intended for configuring and monitoring the i2C bus extension link and so treats the combination of the local and remote LTC4331 devices as a single logical device.  Therefore, the control interface is only accessible the local side bus.
      

      

      When enabled, the Packet Error Correction is only applied for data to/from control interface.  Other than the address translation for the remote side bus, the extension link is entirely transparent and just passes data through as is received.
      

      

      The LTC4331 link can detect some link errors (e.g. loss of communications or malformed data packets between the local & remote LTC4331s) and will report this as a fault; however, it is not performing error correction/detection on the I2C data being sent across the link.
      


      Eric
      
			
      

		
			
	      

		
		
	
      
	
      
		
      
			
		
      
	
      
	
      
		
						
						
						
						
				
				
		
		
      
			
		
      
	
      

      

      • 

	
    



Reply

      


    • 
	
      



	
			
		
	



      
	
      
		
      
							
					
      
		
      
			
													0
							
			
				
									
							        
			
			
			
      •  Analog Employees  
      
            
			                            
                                                                                                                        
            
				
			
            
					
      
	
      

		
		
      
					
      The control interface is intended for configuring and monitoring the i2C bus extension link and so treats the combination of the local and remote LTC4331 devices as a single logical device.  Therefore, the control interface is only accessible the local side bus.
      

      

      When enabled, the Packet Error Correction is only applied for data to/from control interface.  Other than the address translation for the remote side bus, the extension link is entirely transparent and just passes data through as is received.
      

      

      The LTC4331 link can detect some link errors (e.g. loss of communications or malformed data packets between the local & remote LTC4331s) and will report this as a fault; however, it is not performing error correction/detection on the I2C data being sent across the link.
      


      Eric
      
			
      

		
			
	      

		
		
	
      
	
      
		
      
			
		
      
	
      
	
      
		
						
						
						
						
				
				
		
		
      
			
		
      
	
      

      

      • 


    


Children
	
    No Data