Ethernet Global Data Operation; Egd Producer; Egd Consumers; Figure 33: Producing & Consuming Ethernet Global Data - GE RX3i User Manual

Chapter 5. Ethernet Global Data

Ethernet Global Data Operation

5.1
Ethernet Global Data is data that is automatically sent from one Ethernet device to one or more others. Once
Ethernet Global Data has been configured, the data is sent automatically during system operation. No program
interaction is necessary to produce or consume the global data.
The device that sends the Ethernet Global Data is called the producer. Each device that receives Ethernet
Global Data is called a consumer. Each unique Ethernet Global Data message is called an exchange (also
sometimes referred to as a page).
An Ethernet Interface can be configured to both produce and consume Ethernet Global Data at the same time,
using separate exchanges.

EGD Producer

The producer of an exchange periodically sends new samples of data from its local internal memory. The
producer of an exchange is uniquely identified by its Producer ID. The Producer ID can be expressed as a
dotted-decimal number (for example, 0.0.0.1). Even when expressed in IP address form, it is not used as an IP
address. It is used to identify a particular PLC on the network. Since the Producer ID identifies only the PLC
producing the exchange, it doesn't matter how many Ethernet Interfaces are installed in that PLC.
When using the EGD configuration server, each PLC that transfers EGD must be assigned a Producer ID even if
that PLC produces no exchanges. The Producer ID uniquely identifies each EGD device in the configuration
server and must be present if the server is used.

EGD Consumers

A consumer is a device that will update its local internal memory based on the data in an exchange. The
consumer is identified at the producer by an IP Address, a Group ID, or a Subnet Mask, depending on the
Destination Type selected.
The Consumed Exchange configuration allows "selective consumption" of a produced EGD exchange. The
consumer takes in the whole exchange from the network but does not need to send all of the exchange to the
PLC memory. This feature is called Selective Consumption. A Consumed Exchange can be set to ignore the data
ranges (variables) that are not needed.
70 PACSystems* RX7i & RX3i TCP/IP Ethernet Communications User Manual
PLC1 - Producer
P
Exchange
Figure 34: Producing & Consuming Ethernet Global Data
PLC2 - Consumer
C
Ethernet Network
GFK-2224Q