● After it is confirmed that connection 1 is established in master mode (X90) and no
transmissions are currently being executed for the same port (Y90), the RECV instruction is
started.
● The UNITSEL instruction is used to specify a slot number (LAN port: U100) and the
connection number (U1).
● In the RECV instruction, specify and execute the type of MODBUS command and partner
station number (H0301), starting address (H0), data amount (U2), and PLC's starting
address to store the data (DT100). Check addresses of connected devices in the instruction
manuals of devices.
R0
Master
communication
clear to send flag
R100
UNITSEL
U100
U1
RECV.US
DT0
U2
DT100
H301
H0
X90
Y90
Master
communication
sending flag
R100
RECV
execution
Settings for the communication
port
S1: CPU LAN port (U100)
S2: Connection 1 (U1)
RECV execution start conditions
Clear to send flag: ON
Sending flag: OFF
RECV instruction execution
S1: MODBUS command (H03)
Partner station no. (H01)
S2: Data address (H0)
n:
Data amount (U2)
D1: Data storage area (DT100)
D2: Execution result code (DT0)
(
(
)
)
DF
S1
S2
S1
S2
n
D1
D2
■
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
processing
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.
15.7 RECV (MODBUS Master: Function Code Specification)
WUME-FP7CPUPGR-12
15-49
Summary of Contents for FP7 Series
Page 2: ... MEMO 2 WUME FP7CPUPGR 12 ...
Page 18: ... MEMO xviii WUME FP7CPUPGR 12 ...
Page 52: ... MEMO 1 34 WUME FP7CPUPGR 12 ...
Page 104: ... MEMO 2 52 WUME FP7CPUPGR 12 ...
Page 123: ...3 9 ANS AND stack WUME FP7CPUPGR 12 3 19 ...
Page 125: ...3 10 ORS OR Stack WUME FP7CPUPGR 12 3 21 ...
Page 129: ...3 11 PSHS Push stack RDS Read stack POPS Pop stack WUME FP7CPUPGR 12 3 25 ...
Page 190: ...3 26 JP LBL Jump Label 3 86 WUME FP7CPUPGR 12 ...
Page 239: ...Name Description SR8 ER 3 46 ST ST ST ST ST ST Data Comparison Start WUME FP7CPUPGR 12 3 135 ...
Page 246: ... MEMO 3 142 WUME FP7CPUPGR 12 ...
Page 258: ... MEMO 4 12 WUME FP7CPUPGR 12 ...
Page 304: ... MEMO 5 46 WUME FP7CPUPGR 12 ...
Page 321: ...Name Description ER 6 7 DIVFP2 Division FP2 Compatible WUME FP7CPUPGR 12 6 17 ...
Page 348: ... MEMO 6 44 WUME FP7CPUPGR 12 ...
Page 388: ... MEMO 7 40 WUME FP7CPUPGR 12 ...
Page 438: ... MEMO 8 50 WUME FP7CPUPGR 12 ...
Page 450: ... MEMO 9 12 WUME FP7CPUPGR 12 ...
Page 520: ... MEMO 10 70 WUME FP7CPUPGR 12 ...
Page 602: ... MEMO 11 82 WUME FP7CPUPGR 12 ...
Page 622: ... MEMO 12 20 WUME FP7CPUPGR 12 ...
Page 650: ... MEMO 13 28 WUME FP7CPUPGR 12 ...
Page 1160: ... MEMO 18 66 WUME FP7CPUPGR 12 ...
Page 1188: ... MEMO 19 28 WUME FP7CPUPGR 12 ...
Page 1220: ... MEMO WUME FP7CPUPGR 12 ...
Page 1221: ... MEMO WUME FP7CPUPGR 12 ...