7 APPLICATION INSTRUCTIONS
7.20 Data Processing Instructions
945
7
Processing details
• These instructions generate the CRC value for (n) 8-bit data (unit: byte) starting from the device specified by (s), and store
the CRC value to the device specified by (d). "X
16
+ X
15
+ X
2
+1" is used in the generator polynomial of the CRC value
(CRC-16). The 16-bit conversion mode and 8-bit conversion mode are available for these instructions. The conversion
mode can be selected by turning on or off SM772.
• If the value specified in (n) is 0, no processing is performed.
• These instructions calculate the CRC (cyclic redundancy check) value which is an error check method used in
communication. In addition to CRC, there are other methods to check an error, such as parity check and sum check
(checksum). For obtaining the horizontal parity value and sum check value, the CCD(P) instruction is available. (
• The operation in each conversion mode is described below.
■
16-bit conversion mode (while SM772 is OFF)
In this mode, the CRC operation is executed for upper 8 bits (in units of byte) and lower 8 bits (in units of byte) of the device
specified by (s). The operation result is stored to 16 bits in one device specified in (d).
Ex.
When (n)=6
In 16-bit conversion mode, the six bytes in the following shaded portion become an operation target. The CRC value is
determined as "A57BH", and therefore "A57BH" is stored in the device specified by (d).
■
8-bit conversion mode (while SM772 is ON)
CRC operation is executed only for lower 8 bits (lower byte) of the device specified by (s). With regard to the operation result,
lower 8 bits (in units of byte) are stored to the device specified by (d), and upper 8 bits (in units of byte) are stored to a device
specified by (d)+1.
Ex.
When (n)=6
In 8-bit conversion mode, the six bytes in the following shaded portion become an operation target. The CRC value is
"BDA1H" and therefore "A1H" is stored in the device specified by (d) and "BDH" is stored in the device specified by (d)+1.
Operation error
Error code
(SD0)
Description
3405H
A digit other than 4 is specified in the digit-specified bit device in (s) and (d).
FFH
FFH
7FH
F9H
D0
24932
D1
4219
D2
-1333
D3
-1
D4
32761
27H
10H
D5
10000
61H
61H
64H
64H
10H
10H
7BH
7BH
FAH
FAH
CBH
CBH
61H
64H
10H
7BH
FAH
CBH
Upper
Lower
Decimal
Hexadecimal
61H
64H
64H
10H
7BH
7BH
FAH
CBH
CBH
FFH
FFH
FFH
7FH
F9H
F9H
D0
24932
D1
4219
D2
-1333
D3
-1
D4
32761
27H
10H
10H
64H
7BH
CBH
FFH
F9H
10H
D5
10000
Upper
Lower
Decimal
Hexadecimal
Содержание MELSEC iQ-R Series
Страница 1: ...MELSEC iQ R Programming Manual Instructions Standard Functions Function Blocks ...
Страница 2: ......
Страница 24: ...22 INDEX 2092 INSTRUCTION INDEX 2093 REVISIONS 2104 WARRANTY 2105 TRADEMARKS 2106 ...
Страница 34: ...32 MEMO ...
Страница 35: ...33 PART 1 PART 1 OVERVIEW This part consists of the following chapter 1 OVERVIEW ...
Страница 68: ...66 1 OVERVIEW 1 5 Precautions on Programming MEMO ...
Страница 204: ...202 5 SEQUENCE INSTRUCTIONS 5 3 Output Instructions Operation error There is no operation error ...
Страница 470: ...468 6 BASIC INSTRUCTIONS 6 6 Data Conversion Instructions Operation error There is no operation error ...
Страница 472: ...470 6 BASIC INSTRUCTIONS 6 6 Data Conversion Instructions Operation error There is no operation error ...
Страница 479: ...6 BASIC INSTRUCTIONS 6 6 Data Conversion Instructions 477 6 Operation error There is no operation error ...
Страница 504: ...502 6 BASIC INSTRUCTIONS 6 7 Data Transfer Instructions Operation error There is no operation error ...
Страница 518: ...516 6 BASIC INSTRUCTIONS 6 7 Data Transfer Instructions Operation error There is no operation error ...
Страница 520: ...518 6 BASIC INSTRUCTIONS 6 7 Data Transfer Instructions Operation error There is no operation error ...
Страница 754: ...752 7 APPLICATION INSTRUCTIONS 7 9 Real Number Instructions Operation error There is no operation error ...
Страница 756: ...754 7 APPLICATION INSTRUCTIONS 7 9 Real Number Instructions Operation error There is no operation error ...
Страница 758: ...756 7 APPLICATION INSTRUCTIONS 7 9 Real Number Instructions Operation error There is no operation error ...
Страница 760: ...758 7 APPLICATION INSTRUCTIONS 7 9 Real Number Instructions Operation error There is no operation error ...
Страница 895: ...7 APPLICATION INSTRUCTIONS 7 16 Ramp Signal Instruction 893 7 Operation error There is no operation error ...
Страница 917: ...7 APPLICATION INSTRUCTIONS 7 20 Data Processing Instructions 915 7 Operation error There is no operation error ...
Страница 919: ...7 APPLICATION INSTRUCTIONS 7 20 Data Processing Instructions 917 7 Operation error There is no operation error ...
Страница 1415: ...13 SFC PROGRAM INSTRUCTIONS 13 1 SFC Control Instructions 1413 13 Operation error There is no operation error ...
Страница 1448: ...1446 14 REDUNDANT SYSTEM INSTRUCTIONS 14 2 Disabling Enabling System Switching MEMO ...
Страница 1795: ...25 TYPE CONVERSION FUNCTIONS 25 1 Converting BOOL to WORD 1793 25 Operation error There is no operation error ...
Страница 1805: ...25 TYPE CONVERSION FUNCTIONS 25 10 Converting WORD to DINT 1803 25 Operation error There is no operation error ...
Страница 1819: ...25 TYPE CONVERSION FUNCTIONS 25 21 Converting INT to DWORD 1817 25 Operation error There is no operation error ...
Страница 1950: ...1948 32 STRING FUNCTIONS 32 2 Extracting String Data From the Left Right Operation error There is no operation error ...
Страница 1972: ...1970 33 TIME DATA TYPE FUNCTIONS 33 4 Division MEMO ...
Страница 2067: ...APPX Appendix 5 PID Control Program Examples 2065 A 252 Set PID control data for loop 2 ...
Страница 2082: ...2080 APPX Appendix 6 Process Control Program Examples 129 Set the default value of the loop tag ...
Страница 2093: ...APPX Appendix 7 List of Loop Tag Memory Areas Used by Process Control Instructions 2091 A MEMO ...
Страница 2109: ......