Set 1756-EN2T IP Address with MSG block?

[BAJ]

So I have code to read the IP address of a 1756-EN2T with a MSG block - Get Single Attribute.

Does anyone know where to find the MSG block settings to set the IP address?

Also wondering if I can set the PLC Name with a MSG block?

I bet there's some good documentation this somewhere, I've just been unable to locate it.

Thx,
-Brad

 

[tlf30]

The IP address can be set using a
The set single attribute service with the same settings as the get single attribute, but the struct you get from the get single attribute is what you will send to the module to set the IP.

Setting the name of the PLC requires a licensed connection which is Rockwell specific and beyond the scope of what can be discussed here. Unless you mean the hostname, which is a set single attribute message just like the IP address.

 

[BAJ]

The IP address can be set using a
The set single attribute service with the same settings as the get single attribute, but the struct you get from the get single attribute is what you will send to the module to set the IP.

Setting the name of the PLC requires a licensed connection which is Rockwell specific and beyond the scope of what can be discussed here. Unless you mean the hostname, which is a set single attribute message just like the IP address.

I had thought the same, but it didn't work. I get error code 16#000e.

Do you know if there needs to be any changes to Class, Instance, or Attribute settings?

 

[BAJ]

File didn't attach. Here's my MSG block properties window.

 

[BAJ]

Nevermind, I see my own problem. Somehow the byte size got set back to 1, should be 72 bytes.

 

[tlf30]

Yep, you got it.

Were you interested in changing the PLC name on the processor or the hostname of the EN2T?

 

[BAJ]

It would be nice to have a list of attributes that are available through the MSG block. Does anyone know of such a list?

 

[BAJ]

I'd like to change the controller name that shows up in RSLinx.

 

[tlf30]

Ah, yeah. that is something that is technically possible without renaming the project, and in doing so will also change the text on the LCD that shows the name of the controller.

The better option is to just rename the entire project. To do this go offline, go to controller properties and change the name listed there. After that you will need to download the change to the controller.

When renaming just the controller via messages:
If the firmware is v20 or higher then it requires a licensed connection (which is how Studio 5000 sends privileged messages to the controller). Firmware v19 or lower can be done with a regular CIP connection. In both cases you will run into project upload and download issues as Studio/RSLogix 5000 sees the PLC name being different as an integrity issue, and different versions handle this more poorly than others (v23 and v24 make the upload/download almost impossible) I have found that very old versions like 16 do not care if the PLC name is different from the project, but I still highly recommend NOT taking this route.

 

[tlf30]

It would be nice to have a list of attributes that are available through the MSG block. Does anyone know of such a list?

Sorry, missed this reply and just saw it in my email.

There is no list. While the values may seem a bit arbitrary they actually represent how the code in the PLC is structured internally.

The service code is what function in the object you are calling. The class code is a unique ID of what object type you are running the function in. The instance is the ID of a specific instance of that class, or an instance of 0 is the static instance of the class. And the attribute is the ID of a field/variable in the class.

Basically the message instruction provided by the PLC is a way of performing a function on a variable in an object in memory. There are far more advanced CIP messages that can operate of the PLC different from what the MSG instruction provides, but many things can be accomplished using the MSG instruction.

There is no official list of classes, or which services exist for each class, of what instances exist for each class by default, or even what attributes exist for each class. But there are technotes on Rockwell's support site that give insight on what exist, and if you spend many hours you can discover a lot of undocumented objects, what services they support, and what attributes exist in them. Unfortunately this comes at the risk of temporary or permanently damaging the hardware. I have never got in a situation where I could not recover a module, but I have been close!

Any object not documented by Rockwell is not supported by them and is subject to change in future releases, thus it is unwise to use them in logic. Internally though the controller and studio 5000 are using them.

There are a couple of us of the forums that can assist with undocumented messages. Mostly JeremyM and myself. I have hundreds of pages of notes on perhaps a hundred different undocumented cip classes across over a dozen different Rockwell products. Unfortunately due to the complexity of CIP, a simple list would not be sufficient to document the available functionality.

 

[xGlory7]

The IP address can be set using a
The set single attribute service with the same settings as the get single attribute, but the struct you get from the get single attribute is what you will send to the module to set the IP.

Setting the name of the PLC requires a licensed connection which is Rockwell specific and beyond the scope of what can be discussed here. Unless you mean the hostname, which is a set single attribute message just like the IP address.

Could you please provide more details about the logic/code?

 

[tlf30]

@xGlory7 what specifically are you trying to accomplish?

 

[xGlory7]

@xGlory7 what specifically are you trying to accomplish?

I want to assign a specific
IP address / Subnet Mask / gateway address
for EN2T automatically when connected to a specific slot.