Mitsubishi Electric MELSEC-Q/L - Reading Oldest Data from Tables

500
7 APPLICATION INSTRUCTIONS
7.7 Data Table Operation Instructions
Reading oldest data from tables
FIFR(P)
Processing details
• Stores the oldest data ((D)+1) input to the table designated by (D) at the device designated by (S). After execution of the
FIFR(P) instruction, the data in the data table is all compressed up by one block.
• Provide an interlock circuit not to execute the FIFR(P) instruction when the value stored in (D) is 0.
Operation error
• In any of the following cases, an operation error occurs, the error flag (SM0) turns on, and an error code is stored in SD0.
(S): Head number of the devices where the data read from the table will be stored (BIN 16 bits)
(D): Head number of the table (BIN 16 bits)
Setting
data
Internal device R, ZR J\ U\G Zn Constant Others
Bit Word Bit Word
(S)   
(D)   
Error
code
Error details Q00J/
Q00/
Q01
QnH QnPH QnPRH QnU LCPU
4100 The FIFR(P) instruction was executed when the value of (D) was 0. 
4101 The data table range has exceeded the range of the corresponding devices
at execution of the FIFR(P) instruction.

Basic
Process
High
performance
Redundant Universal LCPU
Command
Command
FIFRP
FIFR
S
S
FIFR
FIFRP
D
D
+1
+2
Data table
Number of stored
data blocks
5432
1234
3
0
0
+3
4321
Stores 0.
+4
+1
+2
Data table
1234
4321
2
0
0
+3
0
5432
+4
D
D
D
D
D
D
D
D
D
D
S