Mitsubishi Electric MELSEC-Q Structured Programming Manual page 21

FXCPU Structured Programming Manual
[Device & Common]
3. FX PLCs
3S
Built-in device memory(RAM, EEPROM)
Contact image memory
Input relay (X)
Auxiliary relay (M) State relay (S)
Timer contact, time counting coil, reset coil (T),
counter contact, counting coil and reset coil (C)
Built-in program memory(EEPROM)
Parameter
Sequence program
Comment
File register (D)
CPU
[Bit device memory]
Output relay (Y)
The PLC automatically recognizes attachment of
an optional memory (when the power is turned ON),
and isolates the built-in program memory.
(The PLC gives the priority to the optional memory.)
1.2 Program Memory and Devices
System ROM
[Data memory]
Data register (D)
Timer current value register (T)
Counter current value register (C)
Index register (V and Z)
Optional memory
(EEPROM)
Parameter
Sequence program
Comment
File register (D)
1 Device Outline
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