6 - 7
MELSEC-F
FIXED BUFFER COMMUNICATION (WITH THE PROCEDURE EXIST
CONTROL METHOD)
6
6 - 7
1) Confirm the normal completion of the open processing of connection
No. 2.
2) Upon receiving data from the designated external device (set in the open
processing), the Ethernet module processes the following.
• Stores the received data to the fixed buffer (No. 2) area.
Receive data length
: The head address area of the target fixed
address
Receive data
: Area beginning from the head address of the
target fixed 1
• Fixed buffer receive status signal (BFM#20485 b1)
: ON
• Fixed buffer communication receive result (BFM#1611) : 0001
H
3) Execute the FROM instruction (In program example, the MOV instruction
and the BMOV instruction are used.) to read the received word length
and received data to the PLC.
4) Execute the TO instruction (In program example, the MOV instruction
and the BMOV instruction are used.) to write "0002
H
" in the fixed buffer
communication receive result (BFM#1611).
5) Return "Response" to communication destination.
6) The receive processing is performed.
At normal completion
• Fixed buffer transmission results (BFM#1611)
: 0004
H
At abnormal completion
• Fixed buffer transmission results (BFM#1611)
: 0008
H
POINT
(1) The destination setting (see Section 5.5) for a connection whose parameters
are set with FX Configurator-EN becomes valid when the open completion
signal (BFM#20480 corresponding bit) of the Ethernet module switches from
off to on.
(2) Execute data receiving process when the corresponding connection's bit in
the fixed buffer receive status signal storage area (BFM#20485) of the buffer
memory switches from off to on or when the value "0001
H
" is stored in the
fixed buffer communication receive results (BFM#1610 to #1617).
(3) At abnormal data receiving, each buffer memory status is shown in the
following.
(For connection No. 2)
• The fixed buffer receive completion signal (BFM#20485 b1) remains off.
• The fixed buffer communication receive result (BFM#1611) remains
"0008
H
".
• Data is not stored in the fixed buffer (No.2) area.