Hi,
One of our slave PLC's types is not able to send a correct Ethernet/IP (CIP) message as the master does not respond. The master responds correct to other slave PLC types. In wireshark we can see that with the passing communication the slave sends a (ENIP) List Services request prior to sending a Register Session request and then sending data. The failing PLC type skips the (ENIP) List Services request before sending the Register Session request and the master will not respond.
What makes an Ethernet/IP (CIP) message send or skip a List Services request?
