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MELSEC-Q
1 OVERVIEW
(3) Data communication using the bidirectional protocol
(Details are explained in Chapter 7 and the User's Manual (Application).)
(a) In communication between programmable controller CPUs and
communication with an external device for which transmission/receive
control programming is allowed, data communication is performed in a
sequence of "data transmission and response receipt".
(b) Error check of received data can be performed using the sum-check code,
while the occurrence of a reception error at an external device can be
checked via an ACK/NAK response.
ENQ
Sum check
code
Any data
ACK
Data length
NAK
Error
code
Sending completed normally
Sending completed
abnormall
QJ71E71
RUN
INIT.
OPEN
SD
ERR.
COM.ERR
RD
10 BASE-T
+12V
12G
10BASE
RS-232
MODE
RUN
ERR.
USER
BAT.
BOOT
CH.2
SDA
SG
SDB
(FG)
RDA
(FG)
RDB
RS-422
/485
CH1.
CH2.
CH1.
2
1
3
4
5
6
7
RS-232
USB
Q25HCPU
POWER
MELSEC
PULL
MITSUBISHI
QJ71C 24
(c) ASCII code data can be used for communication using the ASCII-BIN
conversion function.
ASCII-BIN
conversion
Binary
data
Q series C24
Binary
data
ASCII
data
MODE
RUN
ERR.
USER
BAT.
BOOT
RS-232
USB
Q25HCPU
QCPU
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