MITSUBISHI ELECTRIC QJ71C24N - Manual (Page 305)

App. - 11 App. - 11
MELSEC-Q
APPENDIX
(b) Command message and response message
1) The message format used in the data communication using the A
compatible 1C frame is the same as the message format of UC24/C24-S8.
2) Check available commands and devices that can be accessed in
Chapter 8 of the Reference Manual, and access the PLC CPU from the
external device.
3) For the QCPU, only read/write of device memory is possible.
For the range of devices that can be accessed, see Section 5.2.1 of the
Reference Manual.
The devices added to the QCPU, i.e. the latch relay (L), step relay
(S), and file register (R) devices, are accessed using commands for
QnA compatible 2C/3C/4C frames. It is necessary to create new
programs.
(c) Accessing other stations
1) When accessing other station's PLC CPU via the MELSECNET/10,
"Valid module during other station access" must be designated in the
parameter setting by GX Developer.
2) Check the stations that can be accessed in Chapter 5 of the Reference
Manual, and access the PLC CPU from the external device.
3) When it is necessary to access other stations on other MELSECNET/10,
data communication must be performed in a QnA compatible 3C/4C
frame.
Create a new program for the external device side according to Chapter
3 of the Reference Manual.
4) It is not possible to access other stations via the MELSECNET(II)/B.
(d) Transmitting data to the external device by the on-demand function
1) The program for data transmission on the PLC CPU side is different
from when UC24/C24-S8 is used.
Create a new program on the PLC CPU side according to Section 3.11
in the Reference Manual.
2) Data to be sent to the external device is identical to when the UC24/C24-
S8 is used.
(3) Data communication using the non procedure protocol
(a) Data transmission/reception
1) The same data transmission/reception as used by UC24/C24-S8 can be
performed.
2) Create a new program for data communication upon checking functions
and instructions used on the PLC CPU side in Chapter 6 of this manual
and Chapter 11 of the User's Manual (Application).
Data transmission/reception is performed using dedicated instructions.