Panasonic FP7 Series Command Reference Manual page 828

15.5 RECV (MEWTOCOL Master / MODBUS Master)
● Another SEND/RECV instruction cannot be executed for a communication port where master
communication is in progress. Confirm that the "master communication sending flags" (YC to
YF) are OFF, and execute the instruction.
● A SEND/RECV instruction cannot be executed for a port where slave communication is in
progress.
● If there is no response, the "master communication sending flags" (YC to YF) remain ON
during the time-out period set in the CPU configuration.
● Up to 16 SEND/RECV instructions can be executed simultaneously for differing COM ports.
■
Sample program (in the case of CPU with built-in ET-LAN)
● This program sends the command from the LAN port of the CPU unit, reads the data from
the data areas DT400 to DT401 of the external device, and writes the data into the data
registers DT100 to DT101 of the PLC.
● 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 partner station number (U1), starting
address (DT400), data amount (U2), and PLC's starting address to store the data (DT100).
R0
DF
（ （ ） ）
R100
RECV.US
15-34
X90 Y90
Master Master
communication communication
clear to send flag sending flag
UNITSEL
U1 DT400
S1
execution
U100
S1
U2 DT100
S2 n D1
RECV execution start conditions
R100
Clear to send flag: ON
Sending flag: OFF
RECV
Settings for the communication
port
U1
S1: CPU LAN port (U100)
S2: Connection 1 (U1)
S2
RECV processing
DT0
S1: Partner station no. (U1)
S2: Data address (DT400)
D2
n: Data amount (U2)
D1: Data storage area (DT100)
D2: Execution result code (DT0)
WUME-FP7CPUPGR-12