Functional Comparisons Of Cpu Module; Functional Comparisons Between The A0J2Hcpu And Qcpu - Mitsubishi Electric MELSEC-A0J2H Series Handbook

2
REPLACING THE CPU MODULE

2.3 Functional Comparisons of CPU Module

2.3.1 Functional comparisons between the A0J2HCPU and QCPU

Function Description
Executes the sequence program
at specified intervals regardless
Constant scan
of the processing time of the
sequence program.
Retains the contents of the
device when the power supply is
Latch turned off or reset, or when there
(power backup) is an instantaneous power failure
exceeding the allowable
momentary power failure period.
Enables remote RUN/STOP from
Remote
an external switch or peripheral
RUN/STOP
devices.
Stops the operation while
PAUSE
retaining the output status.
When the factor of an interrupt
Interrupt occurred, this function executes
processing the program according to that
factor.
Stores the utility programs or
microcomputer programs written
by the user to the microcomputer
Microcomputer
program area and executes the
mode
various controls and operations
by calling the stored programs
from the sequence program.
The settings for ON/OFF of
Display priority of
ERROR LED at the occurrence of
ERROR LED
error
Operates by saving the
parameters or programs to the
ROM operation ROM to ensure that user
programs are not erased due to
running out of batteries.
Data protection Prohibits reading/writing to the
(System protect, built-in memory of the CPU
keyword module, memory cassette,
registration/ programs within the memory
password card, comments, etc. from
registration) peripheral devices.
Selects the output (Y) status
Output status
during STOP  RUN from re-
settings during
output before STOP or output
STOP  RUN
after operation execution.
Reads/writes data of the built-in
clock of the CPU. The clock data
Clock function is the year, month, day, hour,
minute, second, and day of the
week.
*1 When PLC type in GX Developer changes, the device number will change.
: Usable : Usable, however, a section of the specifications, i.e. setting methods, is different × : Not used
A0J2HCPU QnUCPU
×
Precautions for replacement
Set this function with the special register (D9020) for
A0J2HCPU, and with parameters for QCPU.
–
–
Set the PAUSE enable flag with the special relay
(M9040) for A0J2HCPU, and with the special relay
*1
(SM206) for QCPU.
–
It is recommended to replace the microcomputer
program with a sequence program.
When using utility package instructions, the
corresponding QCPU instructions must be modified.
Target errors vary by model, but the function is the
same.
A0J2HCPU can perform the ROM operation by using
EP-ROM (sold separately).
The Universal model QCPU, whose program memory
is a Flash ROM, does not have to perform the ROM
operation.
A0J2HCPU prohibits the parameters and programs
from being read/written to the user memory by
keyword registration, whereas QCPU prohibits each
file from being read/written by password registration.
The parameter needs to be reconfigured when
replacing A0J2HCPU with QCPU.
A0J2HCPU handles the last two digits of the year
(western calendar), whereas QCPU handles the four
digits.
Reference
sections
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Section
2.4.2
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