Hello Mr.adwo...
You can communicate both of mentioned plc by using Omron Ethernet FINS Protocol.
It is inbulits omron protocol... its very simple for omron model PLCS
Set the IP address in the column of setting portions.. and dont forget put the fins ID As 0 for master PLC CP1H,And also set the home group IP addressfor the slave plc also....for slave FINS id is 1..
THATS ALL, Now you can Use SEND And Receive commands to Read write the PLC values via Ethernet..
for REFERENCE ,PLEASE VISIT THE MANUAL.......
HAVE A GOOD DAY.........
cp1w-eip61_manual.pdf