Modbus TCP - ControlLogix <> S7

We have a need to communicate between a ControlLogix PLC and an S7 PLC on Ethernet. Modbus TCP has been suggested, but I am looking for any suggestions. Ethernet is preferred, because we already have an existing PLC Ethernet Network we can use.

We are looking at an Ethernet Card in the S7 Rack and another Card in the ControlLogix Rack.

We need to exchange Digital and Real/Float Data.

Is Modbus TCP the best option, any other options?

If Modbus TCP is the best option, any recommended Cards?

I appreciate any help and suggestions.

Stu....

Take a look at the Anybus adapters - perhaps a Ethernet/IP slave to a Profinet slave? I have used them a couple of times - quick and easy to set up. http://www.hms.se/products/abx.asp

Do you have to do this one a shoestring budget, or can you spend a little money for simplicity/reliability ?

The users who have installed them say nothing but good things about the OLDI/Prosoft Industrial Message Manager module:
http://www.prosoft-technology.com/content/view/full/13843

I think the Forum favorite would be the Red Lion DataStation Plus.

http://www.redlion.net/Products/HumanMachineInterface/DataStationPlus/DataStationPlus.html

The "DSPLE" model is the basic protocol bridge without a virtual HMI, so it's a little less expensive but uses the same Crimson 3 software.

You'd use the A-B "Native Tag Addressing" driver to communicate with ControlLogix over EtherNet/IP.

Crimson 3 has two Siemens S7-related Ethernet drivers: "Siemens S7-300/400 TCP/IP Master", and "Siemens CP243 via ISO TCP/IP Master".