Panasonic FP7 Series User Manual page 113

R0
DF
（ （ ） ）
R100
RECV.US
(Note 1) Operand [S1] of RECV instruction is specified by combining two hexadecimal digits of MODBUS
function code with two hexadecimal digits of partner device station number.
(Note 2) When the partner device is FP series PLC, Operand [S2] of RECV instruction can be specified using
the device number.
■
Time chart (in the case of SCU)
Master communication
clear to send flag
（XC,XD,XE,XF）
Master communication
sending flag
（YC,YD,YE,YF）
RECV execution
Master communication
sent flag
（Y0,Y1,Y2,Y3）
Data sending
Response reception
processing
● The case of SCU shows the case that it is used in the following combination.
• COM.0 port equipped in the CPU unit
• Communication cassettes attached to the CPU unit (COM.1 to COM.2 ports)
• Communication cassettes attached to the serial communication unit (COM.1 to COM.4
ports)
● The communication cassette (Ethernet type) does not support MODBUS.
WUME-FP7COM-07
8.3 MODBUS RTU Master Communication (RECV)
XC YC
Master Master
communication communication
clear to send flag sending flag
UNITSEL
H0301
S1
Checks that the
flag is ON
Checks that the
flag is OFF
U0
S1
H0 U2 DT100
S2 n D1
R100 RECV execution start conditions
Clear to send flag: ON
Sending flag: OFF
RECV
execution Settings for the communication
port
S1: Slot 0 (U0)
U1
S2: COM1 (U1)
S2
RECV processing
S1: MODBUS code (H03) and
partner station no. (H01)
DT0
S2: Partner station address (H0)
(H0: Respond to 400001)
D2
n: Data amount (U2)
D1: Data storage area (DT100)
D2: Execution result code (DT0)
RECV Instruction executable conditions
Clear to send flag (XC,XD,XE,XF): ON
Sending flag (YC,YD,YE,YF): OFF
Sending flag (YC,YD,YE,YF):
While sending: ON, Sending done: OFF
Sent flag (Y0,Y1,Y2,Y3):
Normal completion: OFF
Abnormal completion: ON
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