Ethernet Global Data (EGD) is a protocol that enables producer (server) to share a portion of its memory to all the consumers (clients) at a scheduled periodic rate. This protocol is developed for
GE Fanuc PLCs to exchange data between PLCs / Drive Systems / HMI/SCADA systems. The protocol uses
UDP over
Ethernet
Ethernet () is a family of wired computer networking technologies commonly used in local area networks (LAN), metropolitan area networks (MAN) and wide area networks (WAN). It was commercially introduced in 1980 and first standardized in 198 ...
layers for exchanging the data. A snapshot of internal reference memory, mediated by an
Ethernet
Ethernet () is a family of wired computer networking technologies commonly used in local area networks (LAN), metropolitan area networks (MAN) and wide area networks (WAN). It was commercially introduced in 1980 and first standardized in 198 ...
interface, is referred to as an exchange. An exchange does not require a reply and is identified by a unique combination of three major identifiers.
* The Producer ID (the producer's IP address)
* The Exchange ID (the exchange's identifier)
* The Adapter Name (the Ethernet interface identifier)
EGD is implemented using classes.
* Class 0 - supports configured exchanges only (implemented in most PACSystems CPUs)
* Class 1 - supports all class 0 services plus programmed EGD exchanges that can be used to read and write other devices on an ad-hoc basis
* Class 2 - supports all class 1 services plus acts as a responder for programmed EGD exchanges (implemented by Ethernet interface module only)
* Class 3 - supports all class 2 services plus static configuration from an EGD configuration server
* Class 4 - supports all class 3 services plus dynamically bound configuration from an EGD configuration server
External links
{{List of Automation Protocols
Industrial computing
Industrial Ethernet