First,let's see modbus:
modbus via ethernet works the same modbus/serial. You should know what the registers you are going to use are. In order to get them read or written you have to make connections to those data members. Please refer to http://zone.ni.com/devzone/conceptd.nsf/webmain/8C5206E2C4C9DFC186256DDD0056E46F?opendocument to get further information on using modbus object.
Second, some comments on Ethernet
The main parameter is an IP address. Lookout's Ethernet Modbus has a second parameter, Identifier, wich permit to have a Ethernet/serial getway and use the nominal 247 serial slaves. Hence, the identifier is like the address in Serial Modbus. Everything else is the same as serial. If you are going to use a direct connection to PLC, remember to use a c
ord with Tx and Rx switched . If you are using existing network infrastructure, ask your network administrator to know what kind of cord you need.
Finally, ethernet timeouts are normally longer than serial, because of ethernet nature.
Hope it helps. If you need more help, let us know.
JSS
