Fnc 84 - Ccd / Check Code - Mitsubishi Electric MELSEC FX3U Programming Manual

FX /FX /FX Series Programmable Controllers
3G 3U 3UC
Programming Manual - Basic & Applied Instruction Edition
16.5 FNC 84 – CCD / Check Code
Outline
This instruction calculates the horizontal parity value and sum check value in the error check methods used in
communication. There is another check method, CRC (cyclic redundancy check) also. For obtaining CRC
value, use CRC instruction.
1. Instruction format
FNC 84
CCD P
2. Set data
Operand type
S S
1
D
n
3. Applicable devices
Bit Devices
Oper-
and System User
Type
X Y M T C S D .b KnX KnY KnM KnS T C D R U \G
S
S
1
S D
2
n
: This function is supported only in FX
Explanation of function and operation
1. 16-bit operation (CCD and CCDP)
The addition data and horizontal parity value of data stored in
addition data is stored to
The 16-bit mode and 8-bit mode are available in this instruction. For the operation in each mode, refer to the
proceeding pages.
Command
input
FNC 84
CCD
→ For complement [NEG (FNC 29) instruction], refer to Section 10.10.
Mnemonic
16-bit Instruction
7 steps CCD
CCDP
Head device number of applicable device
Head device number storing the calculated data
Number of data [setting range: 1 to 256]
Digit Specification
/FX
3U
, and the horizontal parity value is stored to
D
S D n
16 External FX Device – FNC 80 to FNC 89
→ For CRC instruction, refer to Section 24.4.
Operation Condition
32-bit Instruction
Continuous
Operation
Pulse (Single)
Operation
Description
Word Devices
Special
System User Index
Unit
V Z Modify K H
PLCs.
3UC
S
16.5 FNC 84 – CCD / Check Code
Mnemonic Operation Condition
−
−
Data type
16-bit binary or
character string
16-bit binary or
character string
16-bit binary
Others
Con- Real Charac-
stant Number ter String
E " "
to +n-1 are calculated. The
S
+1.
D
11
12
13
14
15
Pointer
16
P
17
18
19
20
485