depends on the interface (e.g. Ethercat, OPC-UA, TCP/IP,...) you're planning to connect the devices.
e.g. Ethercat Master supports in v1.8.0 up to 64 devices and 512 Byte data, you can find this in the feature description of Ethercat Master. You can find this in ctrlX documentation as "EtherCAT Master– Features"