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MELSEC-Q
11 INSTRUCTIONS AND FUNCTIONS
• The maximum number of bytes in the microcomputer program is determined by the
capacity set by the parameter. The head addresses that can be specified are as
follows:
CPU type name
Capacity of the
microcomputer program
Microcomputer program
address
A0J2HCPU
A1SCPU
A1SJCPU
A2CCPU
A52GCPU
Maximum 14 k bytes
&H0000 to &H37FE
A1CPU
A1NCPU
Maximum 10 k bytes
&H0000 to &H27FE
A2CPU (S1)
A2ACPU (S1)
A2NCPU (S1)
A2SCPU
A2UCPU (S1)
A2USCPU (S1)
Maximum 26 k bytes
&H0000 to &H67FE
A3CPU
A3ACPU
A3HCPU
A3MCPU
A3NCPU
A3UCPU
A4UCPU
A73CPU
A7LMS-F
Maximum 58 k bytes for
both main and sub
microcomputer programs
&H0000 to &H7FE
• The maximum number of bytes of the microcomputer program that can be written at
one time is 128 bytes.
The entire microcomputer program can be written by specifying the head address
number and the number of bytes to be written in units of 128 bytes as follows:
Specify %(3)=&HFF, %(4)=128.
Specify %(3)=&H80, %(4)=128.
Specify %(3)=&H0, %(4)=128.
Microcomputer program area
0
128
256
384
Use the data read from the PLC CPU by using the PCRD instruction for the microcomputer
program to be written. If other data is written, the PLC CPU cannot operate normally.