S100 single port Ethernet card may not able to connect over multicast to multiple devices or VFD's.
S100 Ethernet Single - Port Serial Option Card
Unicast support was not implemented until firmware version 3.05. Check
COM06 to see what version Ethernet card you have.
< 3.05 only supports Multicast
≥ 3.05 supports Multicast and Unicast
For S100 1-port
EIP option only, multi cast has some issues when connecting with several VFDs. It
could be unstable.
But unicast
does not have a limitation.
Therefore, we recommend using unicast when connecting
several devices or VFD's.