Fnc 39 - Sfrd / Shift Read [Fifo Control] - Mitsubishi Electric MELSEC FX3U Programming Manual

FX /FX /FX Series Programmable Controllers
3G 3U 3UC
Programming Manual - Basic & Applied Instruction Edition
11.10 FNC 39 – SFRD / Shift Read [FIFO Control]
Outline
This instruction reads data for first-in first-out control.
1. Instruction format
FNC 39
SFRD
2. Set data
Operand Type
S
D
n
*1. "+1" is required for the pointer.
3. Applicable devices
Bit Devices
Oper-
and System User
Type
X Y M T C S D .b KnX KnY KnM KnS T C D R U \G
S
D
n
: This function is supported only in FX
Explanation of function and operation
1. 16-bit operation (SFRD and SFRDP)
+1 written in turn by SFWR (FNC 38) instruction is transferred (read) to
S
1
+1 are shifted rightward by 1 word. "1" is subtracted from the number of data, stored in
S
1
Command
input
FNC 39
SFRDP
328
Mnemonic
16-bit Instruction
P
SFRD
7 steps
SFRDP
Head word device number storing data
(The first word device works as the pointer, and data is stored in
later.)
Word device number storing data taken out first 2 ≤ n ≤ 512
Number of store points plus "1"
Digit Specification
S D
11 Rotation and Shift Operation – FNC 30 to FNC 39
11.10 FNC 39 – SFRD / Shift Read [FIFO Control]
Operation Condition
Continuous
Operation
Pulse (Single)
Operation
Description
*1
2 ≤ n ≤ 512
Word Devices
Special
System User
Unit
/FX PLCs.
3U 3UC
n
Mnemonic
32-bit Instruction
−
−
+1 and
S
Con- Real
Index
stant Number
V Z Modify K H E
, and "n-1" words from
D
Operation Condition
Data Type
16-bit binary
16-bit binary
16-bit binary
Others
Charac-
Pointer
ter String
" " P
.
S