CompactLogic I/O as remote I/O

[patb63 0]

We're looking at upgrading a few systems for one of our customers and I wanted to see if this was possible: Replace an L32E-CompactLogix processor with an L61-ControLogix processor and use some of the existing CompactLogix I/O (second rack) as remote I/O from the ControLogix system. The need for faster processing speed is causing the upgrade to ControLogix, but we'd like to salvage as much of the existing I/O system as possible. As always, thanks for any and all help. Edited 7 Jan 2010 by patb63

[Ken Roach 194]

The only network adapter for 1769 I/O is the 1769-ADN for DeviceNet. This will give you significantly slower I/O updates than the local I/O bus did, so having more processing speed is going to be countered by slower I/O speed. Will a 1768-L43 or -L45 controller give you sufficient improvement in CPU capacity, so you don't have to go all the way to a 1756 controller ?

[patb63 0]

We tested an L-43 processor and saw no significant improvement; we still had overlaps with our tasks when we ran at the speeds we were hoping to achieve. Also, the L-43 processor saw about 95% CPU usage, whilethe L-61 was at about 35%. We may have to change completely to the ControLogix platform, but we were hoping to lower the cost somewhat by using some of the existing CompactLogix I/O. We had also hoped to use Ethernet/IP, but I hadn't found anything except the DeviceNet setup you mentioned.

[Armadillo852 25]

If you have to use external componets, I would look at Beckhoff I/O. We use CompactLogix with Beckhoff I/O because the I/O is fast and easy to setup. It is all Ethernet as well.

[patb63 0]

Thanks for the reply Armadillo, but the problem is in processor capacity/speed, not the I/O.

[lostcontrol 23]

I'm assuming that you have analysed the code, and it is as efficient as it can be?

[patb63 0]

We feel it is......we've converted a lot of it to structured text for speed. Our issue seems to occur at a certain speed threshold of the controlled equipment. Most of the systems work fine, but any that run faster than the threshold limit seem to overtax the processor. Our customers are always trying to speed things up, so we can only try to accomodate that.

[paulengr 44]

This would be the appropriate forum to discuss this. There may be ways to improve the overall system structure (optimizing I/O, tasks) or switching to better algorithms to accomplish the same task.

[patb63 0]

Reviving this topic!!! On previous project, we replaced all the IO, etc. with ControLogix equipment. Now I see that there is a 1769-AENTR that appears to be able to replace the CompactLogic processor and make the 1769 rack a remote rack to a 1756 system. My question for the gurus on here is am I correct in this assumption? Thanks.

[patb63 0]

Reviving this topic!!!</p><p>On previous project, we replaced all the IO, etc. with ControLogix equipment. Now I see that there is a 1769-AENTR that appears to be able to replace the CompactLogic processor and make the 1769 rack a remote rack to a 1756 system. My question for the gurus on here is am I correct in this assumption? Thanks.

[y2kmfic 3]

Patb63.. you are correct. Here is a nice podcast that goes through this.

[Ken Roach 194]

Yes; the 1769-AENTR is a new product in 2014 that provides Adapter-mode functionality over EtherNet/IP. There are a handful of RA Knowledgebase documents that describe the 1769-AENTR, as well as some manuals in the Literature Library. CompactLogix Communication Modules Technical Data http://literature.rockwellautomation.com/idc/groups/literature/documents/td/1769-td007_-en-p.pdf CompactLogix Selection Guide http://literature.rockwellautomation.com/idc/groups/literature/documents/sg/1769-sg001_-en-p.pdf In short: you need RSLogix 5000 v20 and an Add-On profile, it supports up to 30 modules, and the usual rules about power supply placement and module distance ratings need to be observed.

[patb63 0]

Finally got back to this. Thanks for the info.