Message Transfers; Outline Of The Message Transfer Process - Sharp JW-20FL5 User Manual

[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.
1 When a node receives a token, it will send a maximum of one frame of message data before
the cyclic frame data sending.
2 A maximum of 1024 bytes can be sent at one time.
3 The JW-50FL uses an algorithm to prevent nodes from exceeding the allowable refresh cycle
interval for message transfers.
4 The 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.
5 It 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
Node 1
Request
Node 1
Response
Node 2
"1:1" data transfer
Receive
Node 2
"1:N" data transfer
Outline of the message transfer process
7-19
Chapter 7: Computer Link Function
Node 3 Node 4
Receive
Node 3 Node 4
7
Receive