Schneider Electric DS301 manual Client-server relationship

IL•1F CANopen DS301 3 Basics

0198441113586, V2.01, 11.2008

Client-server relationship A client-server relationship is established between 2 devices. The "server" is the device whose object dictionary is used during data ex- change. The "client" addresses and starts the exchange of messages and waits for a confirmation from the server.

A client-server relationship with SDOs is used to send configuration data and long messages.

data
Client
data	Server

Figure 3.8 Client-server relationship

The client addresses and sends a CAN message to a server. The server evaluates the message and sends the response data as an acknowl- edgement.

Producer-consumer relationship The producer-consumer relationship is used for exchanging messages with process data, because this relationship enables fast data exchange without administration data.

A "Producer" sends data, a "Consumer" receives data.

	Consumer
Producer	Consumer
	data
	Consumer
	request
Producer	Consumer
	data
	Consumer

Figure 3.9 Producer-consumer relationships

The producer sends a message that can be received by one or more network devices. The producer does not receive an acknowledgement to the effect that the message was received. The message transmission can be triggered

•by an internal event, e.g. "target position reached"

•by the synchronization object SYNC

•a request of a consumer

For details on the function of the producer-consumer relationship and on requesting messages see chapter 3.4 "Process data communication".

Fieldbus interface 25