7 Applied Instructions
7.27 Extension File Register Control
761
FXCPU Structured Programming Manual
(Basic & Applied Instruction)
1
Outline
2
Instruction List
3
Configuration of
Instruction
4
How to Read
Explanation of
Instructions
5
Basic Instruction
6
Step Ladder
Instructions
7
Applied
Instructions
8
Interrupt Function
and Pulse Catch
Function
A
Relationships
between devices
and addresses
b) When not connecting to a memory cassette
The contents (current values) of extension file registers (ER) stored in PLC's built-in EEPROM having
the same numbers with the extension registers specified by to +n-1 are read, and
transferred to the extension registers (R) specified by to +n-1 stored in the PLC's built-in
RAM.
- Reading and transfer are executed in units of device. Up to 24000 devices can be read and transferred.
Cautions
1. About the allowable number of times of writing operations in memory
Note the following when accessing the extension file registers:
• For the FX
3U and FX3UC PLCs
The memory cassette (flash memory) allows up to 10,000 times of writing operations.
The number of times of writing operations counts up each time the INITR, RWER or INITER instruction is
executed. Do not exceed the allowable number of times of writing operations.
When a continuous operation type instruction is executed, writing operation to the memory occurs for each
operation cycle of the PLC. To avoid this, be sure to use pulse operation type instructions.
The number of times of writing operations does not count up when the LOADR, SAVER or LOGR
instruction is executed. However, the SAVER and LOGR instructions require the target write sectors to be
initialized before executing the instructions. Note that, when initializing by using the INITR or INITER
instruction, the number of times of writing operations in the memory counts up every time the NITR or
INITER instruction is executed.
• For the FX
3G PLCs
The memory cassette (EEPROM) and PLC's built-in memory (EEPROM) allow up to 10,000 times and
20,000 times of writing operations, respectively.
The number of times of writing operations counts up each time the RWER instruction is executed. Do not
exceed the allowable number of times of writing operations.
When a continuous operation type instruction is executed, writing operation to the memory occurs for each
operation cycle of the PLC. To avoid this, be sure to use pulse operation type instructions.
The number of times of writing operations does not count up when the LOADR instruction is executed.
E
E+1
E+2
E+3
E+n-2
E+n-1
+1
+2
+3
+n-2
+n-1
Read (transfer)
s
s
s
s
s
ss
s
s
s
s
s
Extension file registers (ER)
inside PLC's built-in EEPROM
Extension registers (R)
inside built-in RAM
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