Allen Bradley PLC addresses for ethernet communication

ICengineer800

Member
Join Date
Aug 2006
Location
NJ
Posts
3
I am working on setting up a network with a few Allen Bradley PLCs and an ABB DCS. We are using the Allen Bradley Ethernet protocol. The AB PLCs are being supplied by a third party who I requested provide me with a list of the all the available points for monitoring. All of the vendors except one have provided a list with addresses in the format N17:0/0. The one vendor that was different provided addresses in the format W200. ABB responded to me with a comment that this last vendor's data was not useable in that format because the OPC server they are using is only capable of reading the Allen Bradley addresses in first format (I assume the raw data). In order to read this other format they would have to use a second OPC server. This is new territory for me and I don't fully understand why this vendor’s data would be in a different format. ABB seems to think that this vendor was supplying its own OPC server on the PLC end. Does this make sense and can anyone clarify this for me. What do I need to tell this vendor in order for him to provide the addresses in the correct format? Thanks.
 
Last edited:
I am going to step out on a limb here, you stated AB plcs but not specifically which ones so I am going to assume many of them are SLC or similar while the "odd one" is using Contrologix.

The PLC5, SLC500, and Micrologix have fixed data files i.e. N is integer, controllogix does not have this.

What you need to do is get with the "odd one" and determine what he is referencing.
 
The "odd one" is a CompactLogix controller (1769-L35E) while the others that were sent in the correct format were PLC-5. Is it possible for the CompactLogix controller to address its data in the PLC-5 format.
 
Yes, but you will have to set up mapping. Under the Logic tab in RS5000, you will have to click on Map SLC/PLC messages. You will also have to put the L35 on the DH+ network to do this.
 
It sounds like the ABB system can only read AB "Legacy" PLC-5 memory map. If this is the case, then you will need to map the Logix "native tags" to legacy register addresses as Mark says above.
 
Originally posted by Mark Buskell:

You will also have to put the L35 on the DH+ network to do this.

The base network is an Ethernet network. Mark, you seem to be saying that the L35E will only correctly resolve the old style data request format if it comes in on DH+. I thought the Logix engine would resolve those addresses regardless of the comm channel they come in on. Did you specifically mean he needs to use DH+ or was that an inadvertent addition?

Keith
 
You will also have to put the L35 on the DH+ network to do this.

What I am saying is to go from an L35 to a PLC5, there will be some DH+ communications involved. It could be done thru the serial port but I would doubt it due to the slow communications speed.

I don't believe that the L35 can talk directly to a PLC5 because at this time they don't make a module like the 1756-DHRIO.

You could buy additional equipment, ControlLogix Rack, PS, ENBT and DHRIO card and communicate from the L35 to the DHRIO and do it that way.
The PLC-5 will however need to communicate to the ethernet. This can be done by installing an ethernet module in the PLC5 rack. Some PLC-5's do have an ethernet port built right on but I have not used them. Another way would be to use messaging from the PLC5 to some other device and then onto the ethernet. This would still probably be done thru DH+ comms.

It may be that the PLC5 is already talking to the DCS and in that case, you could set up some type of pass-thru communications to talk directly.

Hopefully some other members can chime in and help me out on other methods on how they might do this.
 
To clarify:

The PLC I am having trouble with is a Compactlogix (1769-L35E). The L35 will be connected to the DCS (not a PLC-5) via its ethernet port and an ethernet switch furnished with the ABB DCS. I don't see where the need for the DH+ comes in. I do understand, after reading the responses, that the L35 data format must be mapped to PLC5 format in order for the OPC server in the DCS to read it as the Allen Bradley Ethernet protocol.

Is this correct?
 
MY confusion comes in because you state it is an AB Ethernet, that implies that it can do producer/consumer tags. What you need to do is contact the ABB people to find out what the specifics are concerning communication, best to have them email or fax exactly what they need; then send it to the Controllogix people.
 
ICengineer800 said:
To clarify:

The PLC I am having trouble with is a Compactlogix (1769-L35E). The L35 will be connected to the DCS (not a PLC-5) via its ethernet port and an ethernet switch furnished with the ABB DCS. I don't see where the need for the DH+ comes in. I do understand, after reading the responses, that the L35 data format must be mapped to PLC5 format in order for the OPC server in the DCS to read it as the Allen Bradley Ethernet protocol.

Is this correct?


From what I am hearing the answer is Yes.

The ABB OPC server only supports AB PLC register type of driver, the OPC driver does not support Logix native tags, and/or the people handling this part have not connected directly to Logix PLCs using native tags.
 

Similar Topics

Hi good day Everyone, I have a cimplicity v10 project with 7 to 8k tags communicating with AB PLC through OPC and Rslinx classic. I have this...
Replies
1
Views
82
I am using Allen Bradley PLC 1756-L81E and EIP module 1756-EN2TR for Ethernet/IP communication. My communication works fine but in Get-Attribute...
Replies
2
Views
164
I have a network with 4 PLCs PLC1 is controllogix and PLCs 2-4 are compactlogix and they all need to communicate. The current way I have this...
Replies
8
Views
223
Hi Everyone, I am currently trying to communicate ControlLogix PLCs via EtherNet/IP with Delta V DCS. There is a VIM2 card configured for...
Replies
1
Views
181
Hi everyone. I have an issue with an Allen Bradley PLC model 1769-L30ER. This PLC had a previous program with a different IP address but when I...
Replies
4
Views
492
Back
Top Bottom