RSLogix 13.04 PLC Upgrade

I have a PLC that is version 13, and I want to upgrade it.
Controller firmware is 13.25, using 13.04 software.
It is a 1756-L55


What criteria would you use to upgrade it and how would you choose a new processor?


I know that I need to keep the same 17 slot rack configuration.


There are no servos or any very complicated math functions.



There are some MSG commands to another old RSLogix PLC, though. I think Version 10.


I think the 70 series processors are dual core and the 80 series are quad core. But, beyond that, I do not know any differences or advantages of these models.


The main reason for the upgrade is that some of the DeviceNet nodes on the line have become unreliable and we want to use EtherNet nodes instead. Currently, there are two DeviceNet modules to accommodate the entire line.


There are 29 VFDs and 11 IO/valve banks on the DeviceNet.


I'd like to hear your ideas.


The attached photo will show the current memory usage and the rack configuration.







Thanks.

Of course I'm a bigger fan of tightening screws and cleaning connectors so that the DeviceNet will run forever on the existing hardware, but you've got your decisions too. I'm installing new CANbus for NMEA2000 in a boat that I intend to get 20 more years out of.

The 1756-L55 went up to version 16 firmware, which is about ten years old.

Unless you need an RS-232 serial port, I would use a 1756-L7x controller with an equivalent memory size. Your controller has one of the biggest memory sizes of the 1756-L55 family; 1756-M16 is 7.5 MB.

So the equivalent would be the 1756-L73, with 8 MB of memory. Your application appears to be using only about 1.2 MB total but of course with networked VFDs on EtherNet/IP your I/O memory will go up.

The 1756-ENET Series A had no I/O capability at all in its original firmware, and very little when upgraded to Series B firmware.

The 1756-ENBT is the 2nd generation device. I would recommend a 1756-EN2T module to migrate that networked I/O onto a high-performance card.

MSG instructions and Produced/Consumed Tags will all be fully backwards compatible.

I don't think this system calls for a 1756-L8x; you probably don't need the CIP motion capacity or built-in Ethernet or enhanced security.

In that existing configuration. The ENBT card in the last slot is not being used for anything. I heard they could not get it working. I think they were trying to add I/O. But, I don't know the story.


The ENET card in slot 1 is going to the plant network.


As far as making the DeviceNet work. Well, they want to add an HMI too. And, well, you know. Everyone likes EtherNet, right?


And, I don't think the RS232 port is in use.

Do you think that the various input and output modules firmware revision will work with a newer 1756-L73 CPU? Or would you replace them with newer versions?

Discrete I/O modules should be fully forward compatible since the very beginning of the 1756 platform.

The older 1756-ENET and -ENBT modules will work with a new controller as well, but as I mentioned the higher-capacity 1756-EN2T would be my default selection for I/O control of a large number of VFDs.

If using the 1756-ENBT or -ENET, flash upgrade them to the highest available firmware just for stability and security reasons.

I don't see any need to upgrade the controller. Just replace devicenet with ethernet and you'd be good to go.

Your memory usage in the L55 is not an issue, and your scan time can't be an issue otherwise you'd have said so.

Personally I would just spend your money on upgrading the connectivity, by only replacing comms modules where necessary.

I cannot think of any reason why upgrading comms to remote devices will change your scan time, so why upgrade the processor. If it ain't broke, don't fix it ....

I was under the impression that the L55 with Version 13 firmware was not very mature as far as the EtherNet I/O was concerned. And, I will have around 50 Ethernet nodes.

It's been so long since I used RSLogix 5000 version 13, I don't recall how many EtherNet/IP I/O connection objects it supports. If you have drives that have Add On Profiles or even EDS-based Add On Profiles, you'll want software that supports them effectively, which will surely be v16 or higher.

There's also some value to having software that is well-supported in Windows 10.

What exact VFDs and I/O devices are on the DeviceNet networks ?

Currently, they are AB Powerflex 4 series, and 160 series VFDs. Will be upgrading to the new Yaskawa V1000 VFD. I think it is a GA250. They are obsoleting the V1000 series.


Then there are the 1798-ADN modules that have 1798-IB8 input modules on them. We will likely be upgrading these to SMC inputs. (Maybe EX600 series)


There are a few Flex I/O nodes as well. They will stay the same. I will just change the 1794-ADN to the EtherNet version.



Then there are the SMC EX250 series DeviceNet Valve Banks. Shown as "Unknown" in RSNetworx. I'm still looking at what I will upgrade these to.



It's using MSG commands to another PLC that is V10, I think. Over the ENET module in Slot 1.

Also be aware that the L8x, with built in ENET, is usually a favorable cost over a L7x + EN2T. It also frees up a slot for future use.