11-1

Chapter 11: SEND/RECEIVE function

Chapter 11: SEND/RECEIVE function

The SEND/RECEIVE functions are exclusive SHARP functions. These can only be used between PCs equipped with FL-net modules (board).

Note: The SEND/RECEIVE functions can be used only when a JW30H, JW50H/70H/100H, or a J- board (Z-500 series) is used as the host PC. This function cannot be used with the JW20H or J- board (Z-300 series).

The SEND/RECEIVE functions allow the exchange of data between certain nodes within a specified maximum time. The SEND function is used to declare a target node and write data from that node. The RECEIVE function is used to declare which node will return data to the node issuing the call and then it receives the data.

[An example of the SEND function]

 

 

 

 

 

Request to write

 

 

 

 

FL-net

 

 

 

Response

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Node

 

 

 

 

 

 

 

 

Node

Node

Node

1

2

 

3

4

 

[An example of the RECEIVE function]

 

 

 

 

 

 

 

 

Request to read

 

 

 

 

FL-net

 

 

 

Response

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Node

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Node

Node

Node

1

2

 

3

4

 

- Dedicated instructions are used to execute the SEND/RECEIVE functions.

 

 

 

 

 

 

 

Dedicated

Detail

 

 

 

instruction

 

 

 

 

 

 

 

 

 

 

 

11

 

F-203

(OPCH)

Declare a station to communicate with (single layer)

 

 

F-204

(SEND)

Write data to the target station

 

 

 

 

 

 

 

 

 

 

F-205

(RCV)

Read data from the target station

 

 

 

 

 

 

 

 

Enter the module No. (port No.)/channel of the host module (board) by using the F-203 (OPCH) instruc- tion. This instruction includes the target node number, and the data memory address in the target node. Enter the data memory address for number of bytes to be transferred using the F-204 (SEND) / F-205 (RCV) instructions. Using these instructions, when the JW-50FL receives a response from the target node, it completes this function automatically. There is no need for special program for the target node PC.

- When using the SEND/RECEIVE functions, the data route between the control module (CPU board) and FL-net module (board) is referred to as a "channel." There are four channels (CH0 to CH3) for each module (board). Each channel can transfer 256 bytes of data. Therefore, in a ladder program, up to four SEND/RECEIVE functions can be executed at once.

[Ex.]

Control module FL-net module (node 2)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

CH0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

CH1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

CH2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

CH3

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Node 3 Node 4 Node 5

Node 6