Changing AB 1756-L73 to L74, L75, etc.

[FourFront 0]

Hello,

I was wondering what the viability and ease of upgrading an AB processor to the next more "powerful" version. Is it a simple plug and play task, or does it require any significant modification to your project to change?

 

My current project is critically faulting the processor in periods of heavy use so we are considering trying the upgrade route. 

 

On a side note, when viewing the  task monitor pie chart in Logix Designer. What does the "comms" portion refer to?

[collinsd70 30]

Hi FourFront.

Welcome to the forum.

Yes this is fairly simple- the normal procedure is to change your PLC type in the "controller properties" window, however...you may have to upgrade your firmware dependant on the version your using compared to the processor you select.

Im not 100% sure on your second question- however this may be the portion of processing power dedicated to the communication process (ie MSG instructions, Consumed and Produced Tagging and Ethernet/IP Comms etc).

This link will provide you with firmware compatibility for the L74.

https://compatibility.rockwellautomation.com/Pages/MultiProductCompareSelections.aspx?crumb=113&versions=56859,56967,56434,56028,55793,55548,55344,54928,54739,54587,54477,54300,54063,53917,51412,55438,55013,54386,53936,51218,50573,50571,51195,50568

Regards

Daniel

 

[Joe E. 259]

What fault are you getting?

You may be able to go to the controller properties and adjust the System Overhead Time Slice (Advanced tab). This is the time the processor uses for comms, messaging, etc.

If you're going to replace PLC, look at the L8xE series. We found that when the L7x came out, the L6x prices started rising significantly. A comparison of list prices between the 7x and 8x processors shows them very similar.

I've never used the task monitor tool so I'm not sure what the COMMS portion of the pie chart means, but I expect it's the resources used to handle communications with other devices. I just tried to use it as a test but it keeps crashing as soon as it connects to a PLC