6 - 4
MELSEC-F
FIXED BUFFER COMMUNICATION (WITH THE PROCEDURE EXIST
CONTROL METHOD)
6
6 - 4
1) Confirm the normal completion of the initial processing.
2) Confirm that the link status is normal between the Ethernet module and
the connected HUB.
3) Confirm the normal completion of the open processing of connection
No. 1
4) Write the send data word count and the send data in the fixed buffer data
area (communication address setting area: BFM#1664 to 2687) by TO
instruction.
5) Write "0001H" in the fixed buffer communication transmission request
(BFM#1610).
6) The size of send data in the fixed buffer (No. 1) area designated by the
send data length is sent to the designated external device (set in the
open processing).
The value in BFM#1610 becomes "0002H".
7) Upon receiving the data from the Ethernet module, the external device
returns a "Response" to the Ethernet module.
8) Upon receiving the "Response" from the external device, the Ethernet
module ends the data transmission.
If the "Response" is not returned within the response monitoring time
values (see Section 5.2), a data send error occurs.
At normal completion
Fixed buffer transmission result (BFM#1610) : 0004H
At abnormal completion
Fixed buffer transmission result (BFM#1610) : 0008H
If the data transmission is abnormally completed, execute the send
process again writing "0001H" in BFM#1610.
R
0002H
Initial processing normally
completed BFM#=0001H
OPEN/CLOSE instruction status
BFM#1602=0005H
Write the send data word
count and the send data
in BFM
TO
Fixed buffer send instruction
and transmission completion
BFM#1610
W
0001H
R
0004H(Success)/0008H(Error issued)
1)
3)
4)
5)
6)
8)
Initial
processing
Send data
writing
Open
processing
Response
receiving
7)
Data sending
Response
Data sending
ACK (TCP only)
ACK (TCP only)
HUB connection is signal
BFM #28 b7 2)