904
7 APPLICATION INSTRUCTIONS
7.19 Check Code Instructions
Processing details
• These instructions perform addition of the data stored in the devices specified by (s) to (s)+(n)-1 and calculate the
horizontal parity, and stores the added data in the device specified by (d) and the horizontal parity in the device specified by
(d)+1. 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.
• If an overflow occurs in the calculated result stored in (d), the following operations are performed. SM700 does not turn on.
• These instructions calculate the horizontal parity value and sum check value as the error check methods used in
communications. There is another check method called CRC (cyclic redundancy check) in addition to the CCD(P)
instruction. (
• The operation in each conversion mode is described below.
■
16-bit conversion mode (while SM772 is OFF)
With regard to (n) data points starting from (s), the addition data and horizontal parity data of upper 8 bits and lower 8 bits are
stored to (d) and (d)+1 respectively.
Ex.
When (n)=6
<Calculation of addition data value>
In 16-bit conversion mode, addition data is determined by adding 6 bytes in the following shaded portion. The addition data is
thus determined as "0315H", and therefore "0315H" is stored in the device specified by (d).
<Calculation of horizontal parity value>
In 16-bit conversion mode, the above shaded portion becomes the horizontal parity calculation target.
The number of ON (1) bits is calculated to determine the parity value which becomes ON (1) when the number of ON (1) bits
is finally odd or OFF (0) when it is finally even. The horizontal parity value is stored in the device specified by (d)+1.
In the following table, 5FH is stored in the device specified by (d)+1.
32767+2=-32767
(7FFFH+0002H=8001H)
-32767+-2=32767
(8001H+FFFEH=7FFFH)
Bit/horizontal parity value
b7
b6
b5
b4
b3
b2
b1
b0
Value
Upper 8 bits of D0
0
1
1
0
0
0
0
1
61H
Lower 8 bits of D0
0
1
1
0
0
1
0
0
64H
Upper 8 bits of D1
0
0
0
1
0
0
0
0
10H
Lower 8 bits of D1
0
1
1
1
1
0
1
1
7BH
Upper 8 bits of D2
1
1
1
1
1
0
1
0
FAH
Lower 8 bits of D2
1
1
0
0
1
0
1
1
CBH
Horizontal parity value
0
1
0
1
1
1
1
1
5FH
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
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: ......