6 - 22 6 - 22
MELSEC-Q
6 DATA COMMUNICATION USING THE NON PROCEDURE PROTOCOL
6.2 Sending Data to the External Device
This section explains data transmission from the PLC CPU to the external device.
6.2.1 Transmission methods
The following shows how to send data in any format using the non procedure protocol.
Transmission area
(buffer memory)
STX A BCDEFGHETX
Transmission data
(02
H
)(41
H
)(48
H
)(47
H
)(46
H
)(45
H
)(44
H
)(43
H
)(42
H
)(03
H
)
A
(41
H
)
G
(47
H
)
E
(45
H
)
C
(43
H
)
STX
B
D
F
H
(02
H
)
(48
H
)
(46
H
)
(44
H
)
(42
H
)
ETX
(03
H
)
10
(0A
H
)(00
H
)
3)
Transmission data
PLC CPU
ETX
H
(03
H
)(48
H
)(41
H
)(03
H
)
External device
ASTX
1) 2)
OUTPUT instruction
Q series C24
Transmission
data count
designation
area
Transmission
data
designation
area
OUTPUT instruction
completion device
OUTPUT instruction
OUTPUT
Transmission instruction
Contents CH1/CH2 Control timing
1) Transmission data is stored in the device designated with the OUTPUT instruction.
2) Control data is stored in the device designated with the OUTPUT instruction.
3) When the OUTPUT instruction is executed, the Q series C24 sends the amount of
data designated by the transmission data count from the transmission data area to
the external device in ascending order of the transmission data area addresses.