682
8 APPLICATION INSTRUCTION
8.22 Data Operation Instruction
CRC calculation
CRC(P)
These instructions calculate the CRC (cyclic redundancy check) value which is an error check method used in
communication. In addition to CRC value, parity check and sum check are available. For obtaining the horizontal parity value
and sum check value, the CCD(P) instruction is available. For the generation of CRC value (CRC-16), these instructions use
"X
16
+ X
15
+ X
2
+ 1" in a polynomial.
Setting data
■
Descriptions, ranges, and data types
■
Applicable devices
Processing details
• These instructions generate CRC value for (n) 8-bit data (unit: byte) starting from a device specified in (s), and store to (d).
The 16-bit conversion mode and 8-bit conversion mode are available for these instructions. For the operation in each
mode, refer to the proceeding pages.
Ladder diagram
Structured text
ENO:=CRC(EN,s,n,d);
ENO:=CRCP(EN,s,n,d);
FBD/LD
Operand
Description
Range
Data type
Data type (label)
(s)
Head device number storing data for which the CRC value is
generated
16-bit signed binary
ANY16
(d)
Device number storing the generated CRC value
16-bit signed binary
ANY16
(n)
Number of 8-bit (1-byte) data for which the CRC value is
generated or the device number storing the number of data
1 to 32767
16-bit unsigned binary
ANY16_U
EN
Execution condition
Bit
BOOL
ENO
Execution result
Bit
BOOL
Operand
Bit
Word
Double word Indirect
specification
Constant
Others
X, Y, M, L, SM,
F, B, SB, S
T, ST, C, D, W,
SD, SW, R
U
\G
Z
LC
LZ
K, H
E
$
(s)
(d)
(n)
• 16-bit conversion mode (while SM8161 is OFF)
In this mode, the operation is executed for high-order 8 bits (1 byte) and low-order 8 bits (1 byte) of a device specified in (s). The operation result is stored
to one 16-bit device specified in (d).
In the following program, conversion is executed as follows:
(s)
(d)
(n)
EN
ENO
s
d
n
CRC
(s)
(d)
(n)
SM400
SM8161
Command
input
16-bit conversion mode
Summary of Contents for MELSEC iQ-F FX5
Page 1: ...MELSEC iQ F FX5 Programming Manual Instructions Standard Functions Function Blocks ...
Page 2: ......
Page 17: ...15 CONTENTS ...
Page 24: ...22 MEMO ...
Page 1050: ...1048 26 TIME DATA FUNCTIONS 26 4 Division MEMO ...
Page 1068: ...1066 29 COUNTER FUNCTION BLOCKS 29 4 Counter Function Block Operation error There is no error ...
Page 1107: ...I 1105 MEMO ...
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