rslinx communication error:

Hello,

Our company bought some basic PLC equipment and RSLogix5000 software to learn how to program PLCS.

The specs are below:
Hardware:
Allen-Bradley Company
Logix5555 Processor with 750Kbyte MEmory
1756-L55M12
1756-L55/A 1756-M12/A LOGIX5555
16.21


Software:
RSLogix5000
V16.03

Computer:
HP
Intel Core2 Duo
2.00GHz
2GB of RAM
Windows XP Pro with SP2 installed

Problem:
I have written a very simple one rung program (on and off button) to test out the PLC in Run mode. However, when I go online, there is quite a long delay. It almost seems as if the program is crashing. Finally it goes online but the software runs very slow. After awhile I get the error:

806-8004-2535
Can’t communicate with RsLinx
RSLogix5000 has been taken offline.

Being new to this topic, I am not sure if the issue is the software, controller or cable? It is important to point out that the cable from the controller to the computer is connected via a serial adapter to USB connector. Could that be a possible issue?

Any suggestions on how to trouble shoot this problem?

Any tips would be appreciated. And if you need more information to analysis the problem better, please let me know.
Thanks,

Simon

Welcome to the Forum

Because this is your first post, It is not clear as to what you do and don't know, so for some questions.

Are you familiar with RSLinx ?
What cable are you using to connect to the PLC ?
What driver are you using in Linx ?
Is the driver running ?
If using Ethernet do you have have an IP address set on PLC, and can you ping it?

Answer these, and add anything else you think of, will help with more replies.

One thing RSLinx won't do, is crash (never crashes) and then to seem to come online. You won't be able to get online if you don't configure your RSLinx driver correctly. This can be done in the RSLinx start-up window under configure access names. Depends what you want to access, and from where.

If your cable being used between the PC and the PLC controller is not approved by a authorised authority, tested to the fact, that it can actually do what is expected of it, then rather get the correct cabling. This might be an issue getting on-line.

Troubling shooting for me, will start at the hardware adaptibility, then looking at the PLC controller communication route w.r.t. RSLinx. Somehow, your PC needs to talk to the controller.

If you can post more info about the cable manufacturer being used and your RSLinx driver configuration for this spesific controller, maybe I can help.

Regards

Manny

Ps. Greetings from sunny South Africa

Hello.

Yes, I will provide more information.

I attached four snapshots of the various configurations that I have.

I followed the tutorials given in RsLogix5000 to set everything up.

I believe the driver is setup correctly since I can download and upload programs. The issue as repeated in my first email is that it is EXTREMELY slow and the communication connection fails very quickly.

The cable I am using between the controller and the laptop is:

1756-cp3 (Logix5000 RS232 Programmer Cable)

I got it off ebay so it is used. I agree, that "could" be the problem.

The DF1 driver does run it just seems quite unstable. Is the serial-to-usb adapter maybe not configured correctly? I included two snap shots of it.

I have one Ethernet module connected. However, for now I have only tried going online with the serial cable. I did try the tutorial to set the Ethernet module up but did not have any success yet. I get stuck at the part where I am supposed to see the Ethernet module in the controller organizer (RsLogix5000 program). Therefore, I am never able to assign an IP address to the controller. However, you can see the ethernet module in rslinx when choosing RSwho.

If there is anything else I can provide, please let me know.

Thanks for the assistance.

Simon
p.s.
SA rocks! Was there in 2007!

You can upload and download using the existing RSLinx driver configuration and the interface cable, no problem. This all should then be honkey-dorey. The cable should be adequate for the purpose.

Try looking at the controller IP address and the Ethernet module IP address. This should correspond. The Ethernet module should assign the IP address to the controller once things are OK. Much better and easier to do an Ethernet connection than a DF1.

I have to go. The misses is calling. Will respond.

Hello Manny,

Thanks for the quick reply.

I heard that before about the performance being better via ethernet.

How can I verify the IP of both the controller and the Ethernet module?

Time for the weekend. I will be back on Wednesday.

Take care and thanks!!!!!

Simon

Hi szimmer

Recommend you get Ethernet working as soon as possible..

I heard that before about the performance being better via ethernet.

Click to expand...

Never a truer word spoken....

I get stuck at the part where I am supposed to see the Ethernet module in the controller organizer (RsLogix5000 program). Therefore, I am never able to assign an IP address to the controller. However, you can see the ethernet module in rslinx when choosing RSwho.

Click to expand...

You will not "see" the ethernet module in the controller organizer unless you put it there yourself. The organizer does not "browse" for devices, it merely tells the controller what modules it is supposed to talk to. The system programmer populates the IO Configuration as required for the modules needed for the application,

And if the controller's project doesn't need to communicate to any remote IO chassis on ethernet, then there is no need to put it into the IO Configuration of the project at all, but most people do, so as to make the slot unavailable for adding another module.

Also, you will not be assigning an IP address to the controller, only to the ENBT module, which serves as a bridge between ethernet and the backplane (ControlBus) of the Logix5000 chassis. ((Imagine the scenario where you have two or more controller modules in the same chassis, they would all communicate through the one ethernet module - one IP address)).

So - you need to configure your ENBT module's IP address and subnet mask, and there are a couple of ways to do it. Easiest way, since you can see it in RSLinx when connected via the serial port of the controller, is as follows ::

Use the Serial driver in RSLinx to browse to the ethernet module exactly as you have it shown on Pic2, and then right-click the mouse. You will then get a small menu (there may be a delay) that allows you to perform "Module Configuration". Once you get this configuration window, choose "Port Configuration".

Enter IP address and subnet mask details :: You must have an IP address that puts you on the same network number as your PC, but with a unique host number :: If you are on a corporate network, seek IT advice for the ENBT address. Set "Auto-negotiate port speed and duplex" if it is not checked.

Then in RSLinx, add a new Ethernet/IP driver, accept the default setting to browse the local subnet.

Then in RSWho, open the Enthernet/IP driver, and the ENBT module should appear automatically when connected. If this works, then ethernet comuunications from RSLogix will work.

Hello,

Once again, thank you for all the good information. I won't be able to try out all these solutions until Friday next week. I will definitely let you know how it works out.

I wish everyone a great weekend!

Simon

I understand the steps and tried them but no luck yet. I am on a corporate network so looks like I will need to contact my network guy to come in and give me the proper address.

However, on the display screen of the Ethernet module, it flashes a number across the display 192.168.10.81

I put that in as the IP address but no luck yet. RSWho says the driver is running but I don't see the module pop up yet when I try to open up the tree in RsLinx.

I will let you know what happens after my network guy comes over.

Simon

You need to use utilities to add the required EDS file to RSLinx in order for RSLinx to see the ethernet module. Once you have done this, shut RSLinx down and start it again. Check your module's revision. The EDS file an be downloaded from AB's website. Add the IP address to the RSLinx driver configuration.

Hi Manny,

EDS file?

Not sure what that is but i will look for it on the AB website.

Thanks,

Simon

I found it at:

http://www.ab.com/networks/eds/cgi-bin/detail.pl?file=EN/0001000C003A0300.eds

I installed it via EDS Hardware Installation Tool.

The ethernet module is complaining that the IP address is a duplicate.

hmm! Definitely stuck here. Unfortunately, my IT guy has not had time yet to help out.

Here are snap shots of my setup if that helps.

Simon

Okay. Now I don't have a duplicate IP warning anymore. Says OK and lists the IP address on the Ethernet module. The Link and OK LEDs are green. The network blinks green.

But still not working right.

hmmm!

Simon

Computer IP address?

It works!

My IT administrator called. It worked in 5 minutes.

And it all makes sense NOW.

So I can see it and it seems to work just fine.

Now the BIG TEST - will it perform better.

I will let you know soon.

Thanks for being patient with me Manny!

Simon