Panasonic FP7 Series Command Reference Manual page 818

15.4 SEND (MEWTOCOL Master / MODBUS Master)
(Note 1) It occurs when an abnormal telegram is received. When there is a format error in the header of an
individual protocol, the communication discards the received data and a response reception timeout
occurs.
(Note 2) It occurs when the communication control I/O relays corresponding to the communication port (master
communication clear to send flag, master communication send active flag, master communication
send done result relay)are not allocated as I/O words of the CPU unit in the I/O map. It occurs only
when the number of user connections of ET-LAN is expanded and this instruction is executed
specifying the expanded connections.
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Sample program (in the case of SCU)
● This program sends the command from the COM1 port of the CPU unit to write the content
of PLC's data registers DT100 to DT101 into the data areas DT400 to DT401 of the external
device (station number 1).
● This program checks that the master mode is on (XC) and that sending is not in progress in
the same port (YC), and then starts up the SEND instruction.
● Using the UNITSEL instruction, specify the slot number (U0) and the COM. port number
(U1).
● In the SEND instruction, specify and execute the source's starting address (DT100) and data
amount (U2), the destination's station number (U1) and starting address (DT400).
R0
DF
（ （ ） ）
R100
SEND.US
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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)
Execute SEND
Master communication
sent flag
(Y0, Y1, Y2, Y3)
Sending data
Response reception
processing
15-24
XC YC
Master Master
communication communication
clear to send flag sending flag
UNITSEL
DT100 U2
S1
Check that the
flag is ON
Check that the
flag is OFF
execution
U0
S1
U1 DT400
n D1 D2
R100
SEND execution conditions
Clear to send flag: ON
SEND Sending flag: OFF
Settings for the communication
port
U1
S1: Slot 0 (U0)
S2
S2: COM1 (U1)
SEND processing
DT0
S: Data storage area (DT100)
n: Sent data amount (U2)
D3
D1: Partner unit no. (U1)
D2: Destination address (DT400)
D3: Execution result code (DT0)
SEND 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
WUME-FP7CPUPGR-12