Chapter 7: Computer Link Function

[9]Message transfers

(1)Outline of the message transfer process

The message transfer process is a function that allows asynchronous data to be exchanged be- tween nodes.

The basic operation of the message transfer process is shown below.

1When a node receives a token, it will send a maximum of one frame of message data before the cyclic frame data sending.

2A maximum of 1024 bytes can be sent at one time.

3The JW-50FL uses an algorithm to prevent nodes from exceeding the allowable refresh cycle interval for message transfers.

4The JW-50FL has a "1:1" message transfer mode for sending to a specified node, and "1:N" message transfer mode to send to all nodes.

5It has a data send confirmation function used to check whether a target node has correctly received the data in a "1:1" message transfer.

Request

7

Response

Node 1

Node 2

Node 3

Node 4

"1:1" data transfer

Request

Receive

Receive

Receive

Node 1

Node 2

Node 3

Node 4

"1:N" data transfer

Outline of the message transfer process

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