Read Tag from Rockwell PLC from Codesys?

OK I have the Win V3 Demo running and I cam connected to it with my programming running.

When I got on line it says my EtherNet/IP Scanner is not running.

Or am I completely off?

I saw your screenshots. It seems there is an issue with the only adapter that you have configured. Can you get the status for the adapter? If you connect to the RaspberryPi with a VNC client, you can install and launch Wireshark (need to do so in super user mode) and you can get the traces to see why the adapter is not communicating, in case the status indicated by Codesys is not helpful.
 
I don't understand what this is for

Code:
Request[8 + numBytesTagName] := 16#01; // Read 1 element LOW BYTE
Request[9 + numBytesTagName] := 16#00; // Read 1 element HIGH BYTE
 
I saw your screenshots. It seems there is an issue with the only adapter that you have configured. Can you get the status for the adapter? If you connect to the RaspberryPi with a VNC client, you can install and launch Wireshark (need to do so in super user mode) and you can get the traces to see why the adapter is not communicating, in case the status indicated by Codesys is not helpful.
I am actually running it in the windows runtime demo at the moment.

But yeah I can launch wire shark.

by adapter I assume it means the PLC in this case, and not my computer NIC.
 
In EtherNet/IP the adapter is what used to be called a "slave" in DeviceNet, and the scanner is what used to be called "master". When Rockwell released ControlNet specification the words master and slave were not used in that specification.
OK,if you have the Windows version of Codesys then yes, the Wireshark trace will be helpful and easy to get. Also, the status for the remote IO EtherNet/IP device from the Codesys status property may tell us why the scanner is not talking to it. Of course I am assuming you did ping test and were able to get a ping reply from the field device.
 
ooooooh so they were being politically correct... Yeah Master/Slave is just less confusing.



Anyways I have wire shark running. I see ICMP packets for pings, but there is ENIP packets being sent when the Program is running, or when I trigger the Function block.
 
here is a screen shot of the Adapter properties.

it says that adapter is not configured, But I don't know what other information it needs.

See Screen shots of Scanner and the Adapter configs. And the adapter Status.

I think I already attached one of the scanner status in a previous post.

2020-11-14_20-11-09.png 2020-11-14_20-22-44.png 2020-11-14 20-24-25.png 2020-11-14 20-26-52.png
 
OK, there are no connections configured for the AB PLC EtherNet/IP adapter. That is why the Codesys scanner cannot initiate communication. Which EDS file did you use to configure the ABPLC adapter? it does not seem to have the connections section described,as the Codesys tool does not allow adding connections.

No_Connections_EIP_Adapter.png
 
I used the Generic EthernetIP device EDS. I assume that is what you mean.


Why do I need those connections aren't they just a mapping of class, Instance and attribute, for cyclical scanning? Isn't that what I am doing manually in the ENIP.Generic_Service function block?

Or is there more 2 and EDS than just that?
 
Last edited:
Oh, I see, this EDS file allows for completely custom configuration of the connection. OK, then you have to actually configure a connection, either using connection path though assemblies, or a symbolic path. In your screenshot above you have not configured a connection, thus the Codesys scanner does not initiate any communication.
 
I used the Generic EthernetIP device EDS. I assume that is what you mean.

Why do I need those connections aren't they just a mapping of class, Instance and attribute, for cyclical scanning? Isn't that what I am doing manually in the ENIP.Generic_Service function block?

Or is there more 2 and EDS than just that?


So you do not want to do cyclic communication? You want to do explicit messaging only?
 
For the moment Yes.


I guess I am a bit confused. Have you read through the whole thread?


In that dialog, is the "symbolic path" I assume means "ANSI Ext. Symbolic Segment" So I still need to use the tag service.

see page 18 of the 1756-pm020_-en-p.pdf



I see no way to set the service request.

To read a tag on AB you need a
Class:= 16#2
Instance:= 16#1
Service:= 16#4c //Tag Request Service



There seems to be no way to request the service with that dialog.


Regardless I still want to start with the Explicit Message FB and then go from there if possible.
 
In that dialog, is the "symbolic path" I assume means "ANSI Ext. Symbolic Segment" So I still need to use the tag service.

I have never communicated the Codesys EtherNet/IP scanner with a Logix tag. It may be possible by defining a connection. If one was able to correctly define the symbolic path see escreen shot in post #24), then theoretically choosing the option "path defined by symbolic name" would allow you to use such path to communicate the Codesys scanner with this tag in Logix. This would create a connection, so it would be connected communication and this would not make use to the tag request service.

Unfortunately I have never done this, so I cannot provide you an example ready to use.
 
OK theColonel26. I have studied the example explained in document 1756-pm020_-en-p.pdf, and I now understand the "ANSI Ext. Symbol Segment". The way this segment is defined is: (1) 0x91, (2) number of ASCII characters and (3) the tag name. I want to try to access Logix tags with connections established through "ANSI Ext. Symbol Segment", when I have time this week. The below screenshot was helpful for me to understand symbol segment syntax. i hope it is helpful for you.

SymbolicPath.jpg
 

Similar Topics

Dear colleagues, I am reaching out for assistance with an issue I am having. I have a code that can successfully insert data from FactoryTalk...
Replies
6
Views
1,006
Hello expert; I want to read the tag values from control logix plc over the WiFi connection. I did it by using Rs link OPC and successfully read...
Replies
1
Views
1,153
Good Evening Gentlemen, we have a FT View SE client running in windows 7 system, now I want to update that system with windows 10. I did the...
Replies
2
Views
2,695
Hi, I'm pretty new to FactoryTalk and PLC's in general. In View SE, is it possible to read a string contained in a UDT and use it in another tag...
Replies
1
Views
1,220
How to solve the error BAD:Configuration Error:Not Limited in Wonderware system management Console Diagnostics
Replies
0
Views
1,987
Back
Top Bottom