1794-L34 to 1769-L30E Retrofit

[bhedding024]

Good morning. I'm looking at switching out an older 1794-L34 FlexLogix PLC. My plan was to take out the FlexLogix PLC and add a 1794-AENT then add a x 1769-L20ER with a 1769-AENT. The question is do i use the local ethernet port on the L30E or add the 1769-AENT to connect to the 1794-AENT? There is also a PV that connects via ethernet but there is a hub in the panel as well. Any advice or recommendations are appreciated.

 

[alan_505]

What are you trying to use the 1769-AENT for as it is designed to add 1769 IO remotely to a CompactLogix or a ControlLogix.

You would use the 1794-AENT and connect it to the ethernet port on the CompactLogix using an address in the range that is on the CompactLogix, if you already have something connected to that port you will need to use an ethernet switch to connect it all together.

 

[bhedding024]

I think i had it in my mind that there was some benefit to using an eternet adapter in the rack versus the adapter local to the controller. Honestly, this logic may quite possibly be antiquated.

 

[ASF]

The 1769-AENTR isn't a ethernet module in the sense you're thinking of. You can't add it to a rack that already contains a PLC. Like the PLC, it must go on the left-hand end of the rack.

Its function is the same as the 1794-AENT - an ethernet adaptor for a remote 1769 IO rack. Not a 1756-ENxT - an ethernet module that can be placed anywhere in a CLX chassis and provide an additional network connection for a PLC elsewhere in the rack.

 

[bhedding024]

Thank you for the insight. Now that I'm thinking about it I think we were doing this with ControlLogix ControlNet processors where we had an Ethernet HMI or something like that. It's been a while. Thank you for clarifying the difference.