Message Communications Path

[Ones_Zeros]

Hello
I have two Compact Logic PLC’s that I’m needing to message data from.
I’m having trouble with the communications path portion of the setup.

- I’m needing to read a valve output from a 1769-L32E Compact controller back to a Compact Logix 1769-L30ER controller via Ethernet.
- The PLC that will be doing the Message Read is the 1769-L30ER. I have this setup but keep getting a syntax error. I’m just trying to read over (1) element that’s a DINT.
- The other PLC that I’m reading the data from is a Compact Logix 1769-L32E controller.

I went on Rockwells site and searched their knowledge base on the comms path setup, but I’m not have any success.

Without adding the remote PLC in the IO tree. What would be the correct syntax?
I can’t take the main PLC offline so I need to just enter the comms path.

I appreciate the help

 

[Robobob]

If you have a Tech Connect contract see Answer ID 1066637, or search for Message CIP Paths for Logix Controllers. in the RA Knowledge Base.

Basically your path will be Port, xxx.xxx.xxx.xxx, Port The port for a CompactLogix controller will be 2
See below.

 

[Ones_Zeros]

Thank you Robobob
I appreciate your help

 

[Ken Roach]

CIP Paths are very straightforward when you're dealing with chassis-based ControlLogix: it's always a series of [Port], [Address] pairs, where the Address can be a slot number, a network node number, or an IP address. The most common Port numbers are 1 (backplane) and 2 (network port).

CompactLogix makes it a little more complicated (though you can use RSLinx to illustrate it to yourself by browsing).

Even though the network connector is physically on the same module as the CPU, the CompactLogix 1769-L32E uses a "virtual backplane" (port 1) and considers the CPU to be in slot 0 and the Ethernet module in slot 1.

For the 1769-L30ER, and other "5370 series" CompactLogix, the network module and CPU are considered to be integrated, and you don't have to specify the virtual backplane and virtual slots.

In your case, the CIP Path starting from the 1769-L32E and going to the 1769-L30ER should be:

1, 1, 2, [IP Address], 1, 0

Because your local Ethernet module is named in the I/O tree, Studio 5000 will substitute its name, so you will see:

LocalEthernet, 2, [IP Address], 1, 0


If the target controller were a 5370 or 5380 series CompactLogix, or a modern 1756-L8xE ControlLogix, you wouldn't need the final hop to the CPU in virtual Slot 0 (but it won't cause a syntax error).

 

[Corsair]

I thought the port number in the path could be 2, 3, or 4 depending on which CompactLogix you are using???

 

[plvlce]

I thought the port number in the path could be 2, 3, or 4 depending on which CompactLogix you are using???

What port number you exit the CompactLogix with depends on which actual port you are using.

iirc it used to always be port 2 for the processor network port (as seen in this case), but the newer 5380 series with 2 separate ethernet ports uses 3 and 4.

For example my connection from one 5069-L320ERS2 to another on the same plant network is 3, [IP Address], 1, 0

 

[Ken Roach]

There are good Knowledgebase and user manual resources that go over every detail, especially of the port numbers on the 5380 series CompactLogix that can be configured both for DLR or dual-port modes.

I just wanted to keep it simple and applicable to this specific question.