Mitsubishi Electronics FX3G User Manual

Page of 964
48
FX
3S
/FX
3G
/FX
3GC
/FX
3U
/FX
3UC
 Series
Programming Manual - Basic & Applied Instruction Edition
2 Overview (Sequence Program)
2.7 Types and Setting of Parameters
2.7.3
Memory capacity setting range
Cautions on setting the memory capacity 
• After changing the memory capacity setting, make sure to write both the programs and parameters to the PLC.
If only the parameters are written to the PLC, program errors (such as parameter error, circuit error and grammar 
error) may occur in the PLC.
• When one block is set in each capacity setting, the memory capacity is reduced by 500 steps.
Each setting should satisfy the following expression:
1) With regard to the comment capacity, up to 50 device comments can be set in one block.
2) With regard to the file register capacity, up to 500 (16-bit) file registers can be set in one block.
3) In the special unit initial value setting, 8 blocks (4000 steps) are used.
4) In the positioning instruction setting, 18 blocks (9000 steps) are used.
5) In the built-in CC-Link/LT setup, 1 block (500 steps) are used.
1. FX
3S
 PLC
Caution
When the memory capacity of the FX
3S
 is 16,000 steps, the program capacity is fixed to 4,000 steps, and the total of
the comment capacity and the file register capacity is limited to 12,000 steps (24 blocks).
The comment capacity is automatically set when the file register capacity is set.
2. FX
3G
/FX
3GC
 PLCs
Caution
FX
3G
/FX
3GC
 PLCs operate in the extension mode when the program capacity is 16,001 steps or more, and operate in 
the standard mode when the program capacity is 16,000 steps or less. The instruction execution time is longer in the 
extension mode than in the standard mode.
Example:
Time required to execute the basic instruction "LD"
Standard mode: 0.21 
µs
Extension mode: 0.42 
µs
~
 Built-in memory capacity       Can be set by changing parameter
Memory capacity
setting
Unit: Step
Comment capacity setting
Unit: Block
File register capacity setting
Unit: Block
2000
0 to 3
0 to 3
4000
0 to 7
0 to 4
16000
~
20 to 24
0 to 4
~
 Built-in memory capacity       Can be set by changing parameter
Memory capacity
setting
Unit: Step
Comment capacity setting
Unit: Block
File register capacity setting
Unit: Block
Built-in positioning setting
Unit: Block
2000
0 to 3
0 to 3
4000
0 to 7
0 to 7
8000
0 to 15
0 to 14
16000
0 to 31
0 to 14
18
32000
~
0 to 63
0 to 14
18
Memory capacity
setting range
1)
Comment
capacity setting
>
2)
File register
capacity setting
3)
Special unit initial
value setting
4)
Positioning
instruction setting
+
+
+
5)
Built-in CC-Link/LT
Setup 
+