Mitsubishi QJ71C24/-R2 User Manual page 29

1 OVERVIEW
QJ71E71
MELSEC Q25HCPU
RUN ERR.
POWER
MODE
INIT. COM.ERR
OPEN
RUN
SD RD
ERR.
10BASE-T
USER
BAT.
BOOT
10BASE
PULL
USB
RS-232
+12V
12G
MITSUBISHI
QJ71E71 QJ71C24
Q25HCPU
MELSEC
RUN ERR.
POWER
MODE INIT. COM.ERR
CH1.
OPEN
RUN
SD RD
ERR.
10BASE-T
USER
BAT.
BOOT
RS-232
10BASE CH.2
PULL
USB
(FG)
(FG)
RS-232
+12V
12G RS-422
MITSUBISHI
/485
1 - 4
(d) It is necessary to create a sequence program for communication control that
conforms to the external device.
(e) Communication can be performed using an user frame by registering the fixed
format portion of the head and tail sections of a message as an user frame.
• When sending data, the Q series C24 adds an user frame to any data
specified by the user.
• When receiving data, the Q series C24 transfers any data excluding the
user frame to the PLC CPU.
QJ71C24
CH1. CH2.
CH1.
RS-232
CH.2
SDA
1
SG
2
SDB
(FG)
3
RDA
4
(FG)
5
RDB
6
RS-422
7
/485
(f) It is possible to clear the current reception data without interrupting the
transmission processing by using the dedicated instruction "CSET."
(3) Data communication using the bidirectional protocol
(Details are explained in Chapter 7 and the User's Manual (Application).)
(a) In communication between PLC 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.
CH2.
CH1.
ENQ
SDA
1
SG
2
SDB
3
RDA
4
5
RDB
6
7
(c) ASCII code data can be used for communication using the ASCII-BIN
conversion function.
QCPU
Q25HCPU
MODE
RUN
ERR.
USER
BAT.
BOOT
Binary
data
USB
RS-232
When receiving data
Any data format
STX
Any data format
ETX
When sending data
Data length
Any data
Sending completed normally
Error
code
Sending completed
abnormally
ASCII
QJ71C24
data
ASCII-BIN
conversion
Binary
data
MELSEC-Q
ETX
STX
Sum check
code
ACK
NAK
1 - 4