The most likely issue is that the R88D cannot use the Trio as clock master in that Trio firmware version. You must add this command to force the first drive to be Distributed Clocks Master. Set the first drive with DC capability to be the Distributed Clocks Master then start the network.

'Use first DC enabled drive as master clock

ETHERCAT($93, 0, 2, -1, 0)

' Start EtherCAT network

ETHERCAT(0, 0)

Please note that the EtherCAT will perform better when the MC4N, MC464 and MC664(X) is the clock master. So using Omron drives is not reccommended with these products. The Flex-6 Nano and MC6N-ECAT can perform at full synchronisation with the first drive as clocks master so those are the preferred Trio Masters with Omron R88D drives.