Mitsubishi Electric MELSEC FX3U - Page 320

318
FX3G/FX3U/FX3UC Series Programmable Controllers
Programming Manual - Basic & Applied Instruction Edition
11 Rotation and Shift Operation – FNC 30 to FNC 39
11.6 FNC 35 – SFTL / Bit Shift Left
Explanation of function and operation
1. 16-bit operation (SFTL and SFTLP)
For "n1" bits (shift register length) starting from , "n2" bits are shifted leftward ([1] and [2] shown below).
After shift, "n2" bits from are transferred to "n2" bits from ([3] shown below).
Caution
Note that "n2" bits are shifted every time the command input turns ON from OFF in SFTLP instruction, but
that "n2" bits are shifted in each operation cycle in SFTL instruction.
Error
If the transfer source is equivalent to the shifted device in FX3U/FX3UC PLCs, an operation error
occurs (error code: K6710).
An operation error does not occur in FX
3G PLCs.
D
S D
+8
+2
n2 (in the case of "n2=3")
n1 (in the case of "n1=9")
[1]
Overflow (data to
be deleted)
+1
D 
+7 +6
+5
D 
+4 +3 +8
D 
+7 +6
+5 +4 +3 +2
D 
+1
to +5 before shift (n2=3)
D 
[3] Copy
[2]
"n2" bits are
shifted rightward
(n2=3).
+2 to before shift (n2=3)
S 
+2 +1
Before
execution
After
execution
S  S  S 
D  D  D  D  D 
D  D 
S  D 
D  D 
D  D  D  D  D 
Command
input
FNC 35
SFTLP
n1 n2D  S 
S D