The device ranges that can be set when selecting
[MELSEC-FX] as the controller type are as follows.
Input relay (X)
Output relay (Y)
Auxiliary relay (M)
Special auxiliary relay (M)
Timer contact (T)
Counter contact (C)
The bit specification of the
Setting range of each
(except Timer (set value),
Counter (set value))
Data register (D)
File register (D)
Special data register (D)
Timer (current value) (T)
Counter (current value) (C) C0
Timer (set value) (TS)
Counter (set value)
Extension register (R)
Index register (V)
Index register (Z)
Buffer memory (BM)
The word specification of
Setting range of each bit
the bit device
(except Timer contact,
When executing the touch switch function set during the bit
specification of the word device, do not write any data to the
word device through the sequence program.
The device No. must be set in multiples of 16.
Only 16-bit (1-word) designation is allowed.
For CS0 to CS199, only 16-bit (1-word) designation is
For CS200 to CS255, only 32-bit (2-word) designation is
Monitoring or writing is not possible in the continuous device
In addition, setting values of the timer and counter, which are
not used for the program, cannot be monitored. If monitoring
is executed, a reading error occurs.
This is not supported by GT10.
Can be used only for special blocks or special units
compatible with FX
(1) Precautions when using the buffer memory
• When the power supply of the special block or
special module is turned off, the contents of the
buffer memory are initialized, except for some
• When the buffer memory is monitored by the
GOT, the PLC scan time may increase instantly.
• Use the 16 bit specification for the buffer
memory of 16 bit data. Use the 32 bit
-2AD, and FX
specification for the buffer memory of 32 bit data.
If using the 16 bit specification for a buffer
memory of 32 bit data, monitoring and writing
may not be executed normally.
For the data size of each buffer memory, refer to
User's Manual of the special block or special
• When reading from/writing to the special block or
special module by interrupt processing of the
sequence program, monitoring/writing from GOT
to the buffer memory may not be executed
(2) How to select a keyword protection level
For equipment that are allowed to operate the FX
PLC online, 3 levels of protection level can be set.
When monitoring or changing settings by any
online equipment is required, set a keyword
referring to the following.
(a) When setting the keyword only
Select a protection level by the initial letter of
All operation protect: Set a keyword with the
initial letter "A", "D" to "F", or "0" to "9".
Incorrect write/read protect: Set a keyword
with the initial letter "B".
Incorrect write protect: Set a keyword with the
initial letter "C".
(b) When setting the keyword and 2nd keyword
Select a protection level by [Registration
(3) Monitoring availability at each keyword protection
The following shows the device monitoring
availability at each keyword protection level.
When registering the
T, C set
When the T, C set values are specified indirectly, changing
devices is available.
(4) Difference between all online operations
prohibition and all operations prohibition
When specifying all online operations prohibition,
displaying devices and inputting data with
programming tools or GOT are all prohibited.
When all operations are prohibited, displaying
devices and inputting data with the GOT are
enabled while all operations using programming
tools are prohibited.
2. DEVICE RANGE THAT CAN BE SET
When registering the
keyword and 2nd
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