ProSoft Technology MVI69-EGD - Manual (Page 31)

Configuring the MVI69-EGD Module MVI69-EGD ♦ CompactLogix or MicroLogix Platform
GE Ethernet Global Data Communication Module
ProSoft Technology, Inc. Page 31 of 96
November 3, 2008
Multicast Address Assignments
Important: Use Multicast whenever the module produces data to at least two other modules. Using
Unicast for these applications can cause data transmission delay when at least one of the
consumer modules is powered down.
Multicast group addresses 224.0.7.1 to 224.0.7.32 are reserved. The module
does not place this limit for messages but the user should consider using the
reserved group addresses. The following table shows the relationship between
multicast group parameters and IP addresses. Refer to Underlying Protocol
Requirements and Constraints for more detailed information on IP and UDP
addresses.
Parameter IP Address
Group 1 224.0.7.1
Group 2 224.0.7.2
… …
Group 32 224.0.7.32
Important: For Multicast mode, use transmit rates of 1 or 2 for best results.
Consumer Exchange IP address: For consumed messages both Broadcast
and Multicast type messages should be set to the IP address of the producer
generating the specific exchange. The combination of the IP address and the
exchange ID uniquely identify the exchange to the system.
2.4.8 Exch ID
1 to 16383
The Exch ID field defines the Exchange ID for this message, and must be unique
for each node. For produced exchanges, the module IP address and the entered
exchange ID uniquely define the exchange to the network. Defined consumer
exchanges use the IP address in the message along with this exchange ID to
determine which exchange to associate with the message. The parameters
defined in the exchange then determine how much data is present in the
message and where to place it into the module's internal database.
2.4.9 CS Major, CS Minor
This is an optional functionality that can be used to prevent unexpected results
when changes are performed to existing producer and consumer exchanges.
The Configuration Signature consists of two one-byte integer value (CS Major
and CS Minor). The CS Major must be equal for both Producer and Consumer
exchanges. The CS Minor reflects backward compatible modifications made to
an exchange (for example: adding registers to the producer exchange count).
Truncating data within an exchange is not backward compatible and requires a
change in the major number.