Chapter 5. Ethernet Global Data74 PACSystems* RX7i & RX3i TCP/IP Ethernet Communications User Manual GFK-2224QEach device in a group responds to the group’s assigned ID number from 1 to 32.Note: Each device on the network using EGD should have a unique local producer ID. If thedevices using multicast EGD do not have unique local producer IDs, unexpected resultscan occur when using group addressing for EGD exchanges.Each Group ID corresponds to a Multicast (Class D) IP address reserved by the Internet authorities. The defaultMulticast IP addresses used by Ethernet Global Data are:Group ID IP Address Note12...32224.0.7.1224.0.7.2...224.0.7.32For EGD class1 on EmbeddedEthernet Interface ofCPE305/CPE310, Multicastnetwork can include only upto 31 numbered groups.CPE330 & CPE400 EmbeddedEthernet Interface supportsMulticast groups 1 – 32.Note: CPE330 and CPE400 do not support AUP file. All of the configurable AUP parameters forthese CPUs are part of the hardware configuration for the corresponding EmbeddedEthernet interface in PME.Group Multicast IP Addresses used by Ethernet Global Data should not be changed unless the defaults wouldcause a network conflict. If necessary, they can be changed within the reserved range of multicast IPaddresses (224.0.0.0 through 239.255.255.255). The change must be made using an Advanced User ParameterFile.Broadcasting Ethernet Global DataThe same Ethernet Global Data exchange can be sent to all of the consumers on a subnet by configuring theProduced Exchange to use a Destination Type of ”Broadcast”. The “Destination” of that exchange then changesto the value 255.255.255.255. (The Ethernet Interface converts this value to the appropriate subnet broadcastmask for this network.) As with a Group ID, each consumer on the subnet can be configured to use some or allof the exchange.Changing Group ID in Run ModeWith the ability to perform a run-mode store of EGD, it is possible to change the Group ID or Destination Type ofa produced or consumed exchange at run-time. The effects of such changes will depend upon theconfigurations of the local PLC and other devices on your network.BroadcastChanging the Destination Type of a produced exchange from unicast or multicast to broadcast causes samplesto be sent to all nodes on your network. Samples are subsequently processed if the local device has aconsumed exchange configured with matching Producer ID and Exchange ID. Otherwise they are ignored.MulticastChanging the Destination Type of a produced exchange from unicast or broadcast to multicast causes samplesto be sent to a subset of the nodes on your network. Samples are visible to all devices on the network thathave any exchange(s) configured to consume from the specified Group ID. Samples are subsequentlyprocessed only if the local device has a consumed exchange configured with matching Producer ID andExchange ID.This means that modifying a multicast exchange so that it produces to a different Group ID may or may notaffect its consumption. If the remote device has any exchanges configured to consume from the new producerID, consumption will not be interrupted. However, consumption will be affected if the remote device is notconfigured to consume any exchanges from the new Group ID. In the latter case, updates to the consumedexchange configuration will be necessary to resume consumption.
