Mitsubishi Electric MELSEC-Q00U(J)CPU User Manual page 53

(c) Calculation example of memory capacity
The following describes a calculation example of memory capacity when parameters and a program are
Ex.
written to the program memory.
• Conditions
1) CPU module to be written: Q26UDHCPU
2) Writing file: Table below
File name
PARAM.QPA (parameter file)
MAIN.QPG (sequence program)
*1 For file size, refer to Page 50, Section 2.1.3 (4) (a).
3) Reserved area for online change: 500 steps/2000 bytes
• Memory capacity calculation
The memory capacity is calculated in units of file sizes of the CPU module to be written. The file size unit
of the Q26UDHCPU in this example is 1 step/4 bytes. (
1.
Calculation of parameter file size
Since the parameter file size is 464 bytes, 116 steps/464 bytes is occupied on the program memory.
2.
Calculation of program size
The program size is found by: Program size + reserved area for online change. Since a program is stored
in units of file sizes (1 step), only the amount equal to the program size is occupied.
3.
Result
The calculation results of the memory capacities are as shown below.
File name
PARAM.QPA
MAIN.QPG Reserved area for online change
File size
464 bytes
Sequence program size
Total
Total memory capacity
CHAPTER 2 APPLICATION OF PROGRAMMING
*1
File size
464 bytes
525 steps / 2100 bytes
Page 50, Section 2.1.3 (4) (a))
Memory capacity
116 steps (464 bytes)
525 steps
500 steps 1025 steps (4100 bytes)
1025 steps
1141 steps (4564 bytes)
2
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