SLC to Logix Conversion/1747-AENTR

Hello all,
I have a SLC 5/05 system consisting of three local 10 slot racks. We are looking to replace the system, with a CLX but want to keep the I/O using the 1747-AENTR. I have called Ab Tech support but they did not give me a solid answer on the question below.
Do I just need a single AENTR module in place of the 5/05 or do I need one in every rack?
I know there is someone here in the forum that have done this before and can help out.
Thank you.

Hi

I have used this and the way I understand It you have 1 plc but 3 racks is this correct. I had this with two racks And 1 plc. It worked better for me to split the racks anyway but I did ask the question and I was told I would need two cards 1 for each rack. I did not try it with one Ethernet card.
You could leave the plc in place on one of the racks And just use it for mapping to the local I/o and have no other code just to keep the cost down.


Donnchadh

I don't think that the AENTR supports multiple racks yet, but I believe that it is coming, but when i do not know.

Alan

Hi Adam

I have spoken to Rockwell at the automation fair before i used this two years ago and that is were I was told this.
I have read it some where so with your set up you will need 3 cards and you will also have to move two cards as I believe it has to be in the first slot of the rack. You could use the slc 5/05 in the main rack and just use it to map the I/O to the control logix plc. Not sure if you want to do this as you will still have the slc 5/05 but it would be cheaper.

Donnchadh

Hi Adam

Just seen you have a device net card in slot 1, I have never added a device net card with the AENTR card so you may want to check that networks will drill down to your scanner card and that the AENTR will also work with it.

Donncahdh

Hi Adam

I just set one up in logix and looks like you are in luck with the SDN. It has the option to add it in.

The bad news is I cant see how you can add a second or third rack so I would think your good luck ended with the scanner card.

Donnchadh

The release notes for version 2.001 of the 1747-AENTR say that it will support 30 slots and up to 3 chassis. This version is only compatible with RSLogix 5000 v21.

http://literature.rockwellautomation.com/idc/groups/literature/documents/rn/1747-rn656_-en-p.pdf

The User Manual for the 1747-AENTR says specifically that some modules will appear in the I/O module selection list but are not supported by the adapter. This includes the 1747-SDN.

http://literature.rockwellautomation.com/idc/groups/literature/documents/um/1747-um076_-en-e.pdf

I would use a 1788-EN2DN to replace the functionality of the 1747-SDN in this network architecture.

Thanks guys, I just got to reading the 1769-AP001A-EN-P and just as ken specified all the ionformation is there.

Ken, could you please elaborate a little more on the 1788-EN2DN module.
We have six drive that are currently on the device net network, but we are thinking of replacing them with powerflex drives with a 22-comm-e modules.

The 1788-EN2DN is more or less functionally equivalent to a 1756-ENBT and 1756-DNB module, packed into one box. It has a DeviceNet Scanlist, just like any other scanner, and acts as an I/O adapter on EtherNet/IP with ControlLogix.

The most common use for it is in MCCs, where a bunch of drives and starters on DeviceNet are connected to a main ControlLogix over EtherNet/IP.

You can browse through it with RSLinx and RSNetworx for DeviceNet, and send messages through it from a ControlLogix. If you are currently configuring or monitoring the drives using RSNetworx, you can continue to do so if you substituted the 1788-EN2DN for the 1747-SDN.

Hi Adam

I only have ver 20 on the pc I had open last night so to ken I say
Again you have shown the light.
You might keep us updated to how you go with it.

Donnchadh

I've used the AENTR, and yes, you need a module in Slot 0 of every rack. It will not communicate over the interconnect cable.

Also, be very careful as the AENT/R registers every module in the rack as a separate CIP connection to the PLC. It cannot do a rack optimization. PLC processors have a limited number of connections available. Connections are also taken up by HMIs (each Panelview Plus can take up to 4 connections by default), SCADA connections, Copies of RSLogix going online with the program, and messaging connections between PLCs.

From what was posted, you're looking at 27 separate connections just through I/O alone. The typical CompactLogix has a maximum of 32. I bet you're thinking "well 27 is less than 32, so that's great!" Not so fast. Is there a Panelview Plus communicating with it? That's 4 connections PER UNIT. Is there CIP messaging over ethernet in the program? When you fill up processor connections, things stop working. Panelview buttons don't work, and it won't let you go online with the program.

From what I'm seeing, you're going to need at minimum a Control Logix processor (they're available with upwards of 128 connections if not more). You could conceivably get by with the top-end 1769-L36ERM Compact (which allows 48 connections), but even that would be too close for comfort for my taste.

Take a wild guess how I know all this. Hint: It wasn't by reading it in a manual, and it has something to do with my sig quote.

Adam303 said:

Ken, could you please elaborate a little more on the 1788-EN2DN module.
We have six drive that are currently on the device net network, but we are thinking of replacing them with powerflex drives with a 22-comm-e modules.

Click to expand...

I'm going to take a wild guess and say these are 160 series drives? I'm only saying that because I've seen so much of that out there. In fact at my last job I just replaced several 160s with Powerflex 4. Used DSI communication instead of Ethernet but I probably should have used the latter (that 1769-SM2 module is not fun to set up).

Personally, I would check out the PowerFlex 525 series that just came out. Ethernet is built-in on-board. No extra modules to buy (unless you want dual ports). And they can be programmed with a USB cable.

Ken's idea is a good one, but there are some fatal flaws. First, if these are indeed 160 or older series drives, you're still running an obsolete part and new replacements will be hard to find if not very expensive. Second, you're still running Devicenet, which isn't as reliable or as flexible as Ethernet/IP. When it works, it works well, but when it goes down, troubleshooting is a massive pain in the rear. I've seen Devicenet networks go down just from slightly moving one connector, yet other times you can pull the thing right out of the socket and everyone else will work just fine, and plugging the cable back in brings the node right back up again.

Keeping your old drives and network might save some time and money now, but later on you'll have to spend that money anyway plus the extra time to re-write your program. The way I see it, you have a choice between just updating everything now and biting the bullet budget-wise, or wait until some time in the near future when a drive goes down, you can't find any replacements, and you have to re-engineer the system in a rush. I prefer doing things once over doing them over (doesn't always happen that way, but it's what I prefer).

Thank you all for your kind replay, I will keep you posted on the project.