R0
Master
communication
clear to send flag
R100
UNITSEL U100 U1
RECV.US DT0U2 DT100U1 DT400
X90 Y90
Master
communication
sending flag
R100
RECV
execution
RECV execution start conditions
Clear to send flag: ON
Sending flag: OFF
RECV processing
S1: Partner station no. (U1)
S2: Data address (DT400)
n: Data amount (U2)
D1: Data storage area (DT100)
D2: Execution result code (DT0)
DF
S1 S2
S1 S2 n D1 D2
Settings for the communication
port
S1: CPU LAN port (U100)
S2: Connection 1 (U1)
■
Time chart (in the case of CPU with built-in ET-LAN)
Execute RECV
Master communication
sending flag
(Y90 - Y9F)
Master communication
sent flag
(Y70 - Y7F)
Sending data
Response reception
Master communication
clear to send flag
(X90 - X9F)
Check that the
flag is ON
RECV instruction executable
conditions
Clear to send flag (X90 - X9F): ON
Sending flag (Y90 - Y9F): OFF
Sent flag (Y70 - Y7F):
Normal completion: OFF
Abnormal completion: ON
Sending flag (Y90 - Y9F):
While sending: ON
ED instruction executed following
response reception processing: OFF
Check that the
flag is OFF
■
I/O allocation (in the case of CPU with built-in ET-LAN)
I/O number Name Description
X90 to X9F
Master communication
clear to send flag
Turns ON when a connection is established in the master
communication.
Y90 to Y9F
Master communication
sending flag
Turns ON during sending data based on the SEND/RECV
instruction.
Turns OFF when the ED instruction is executed after the
completion of the response receive processing.
Y70 to Y7F Sent flag
Reports completion result of sending data in genera-purpose
communication or master communication. (Normal completion: 0,
Abnormal completion: 1)
(Note 1) Each contact is used for reading the operation state. Do not write over it with a user program.
■
Precautions during programming (in the case of CPU with built-in ET-LAN)
● Use the UNITSEL instruction immediately before the SEND/RECV instruction to specify a
target connection number for communication.
7.3 MEWTOCOL-COM Master Communication (RECV)
WUME-FP7COM-07 7-13