Mitsubishi QJ71MB91 User Manual

4
MODBUS(R) STANDARD FUNCTIONS
4.2 Frame Specifications
4.2.1 Frame mode
4 - 12
1
OVERVIEW
2
SYSTEM CONFIGURATION
3
SPECIFICATIONS
4
MODBUS(R) STANDARD FUNCTIONS
5
FUNCTION
6
PRE-OPERATIONAL PROCEDURES AND SETTINGS
7
PARAMETER SETTING
8
UTILITY PACKAGE (GX Configurator-MB)
The following is a calculation example in the case where function code 07H is sent to
station No. 2.
Table4.5 CRC calculation procedures
CRC error check procedure 16-bit register (MSB) Flag
(Load the register whose 16 bits are all "1")
02
H(Station No.)
Exclusive OR (XOR)
1111
1111
1111
1111
1111
0000
1111
1111
0010
1101
Shift 1
Generator polynomial
Exclusive OR (XOR)
0111
1010
1101
1111
0000
1111
1111
0000
1111
1110
0001
1111
1
Shift2
Generator polynomial
Exclusive OR (XOR)
0110
1010
1100
1111
0000
1111
1111
0000
1111
1111
0001
1110
1
Shift3
Shift4
Generator polynomial
Exclusive OR (XOR)
0110
0011
1010
1001
0111
0011
0000
0011
1111
1111
0000
1111
1111
1111
0001
1110
0
1
Shift5
Shift6
Generator polynomial
Exclusive OR (XOR)
0100
0010
1010
1000
1001
0100
0000
0100
1111
1111
0000
1111
1111
1111
0001
1110
0
1
Shift7
Shift8
Generator polynomial
Exclusive OR (XOR)
0100
0010
1010
1000
0010
0001
0000
0001
0111
0011
0000
0011
1111
1111
0001
1110
0
1
07H(Function)
Exclusive OR (XOR) 1000 0001
0000
0011
0111
1001
Shift 1
Generator polynomial
Exclusive OR (XOR)
0100
1010
1110
0000
0000
0000
1001
0000
1001
1100
0001
1101
1
Shift2
Generator polynomial
Exclusive OR (XOR)
0111
1010
1101
0000
0000
0000
0100
0000
0100
1110
0001
1111
1
Shift3
Generator polynomial
Exclusive OR (XOR)
0110
1010
1100
1000
0000
1000
0010
0000
0010
0111
0001
0110
1
Shift4
Shift5
Generator polynomial
Exclusive OR (XOR)
0110
0011
1010
1001
0100
0010
0000
0010
0001
0000
0000
0000
0011
1001
0001
1000
0
1
Shift6
Shift7
Shift8
0100
0010
0001
1001
0100
0010
0000
1000
0100
0100
0010
0001
0
0
0
CRC value 12H 41H

Mitsubishi QJ71MB91 Specifications

General

Brand	Mitsubishi
Model	QJ71MB91
Category	Controller
Language	English