Mitsubishi Electronics FX3G User Manual

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3S

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3G

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3GC

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3U

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3UC

 Series

Programming Manual - Basic & Applied Instruction Edition

5 How to Specify Devices and Constants to Instructions

Character strings are classified into character string constants which directly specify character strings in operands in
applied instructions and character string data.

A device "character string" directly specifies a character string in a sequence program.
Put half-width characters inside quotation marks (example: "ABCD1234") in specification.
JIS8 code is available.
Up to 32 characters can be specified as a character string.

With regard to character string data, a specified device to the NULL code (00H) is handled as one character string in
1-byte units.
When expressing (recognizing) character string data by bit devices with digit specification, however, 16 bits are
required for data including the NULL code (00H) specifying the end of the character string data because the instruction
length is 16 bits.  (Refer to Example 2 in the step 2 below.)
In the following cases, an operation error occurs in the applied instruction (error code: K6706):
• When "00H" is not specified in the corresponding device range after the source device number specified in an 

applied instruction

• When there are insufficient devices for storing character string data (including "00H" or "0000H" indicating the end 

of the character string data) in the destination devices specified in an applied instruction

1) Character string data stored in word devices

• Example of data which can be

• Example of data which cannot be 

   recognized as character string data

   recognized as character string data

2) Character string data stored in bit devices with digit specification

• Example of data which can be

• Examples of data which cannot be

   recognized as character string data

   recognized as character string data

2nd character

4th character
6th character

00H

1st character

3rd character
5th character

21st character

"00H" indicating the end of

the character string can be

detected.

b15                 b8 b7                   b0

D100
D101
D102

D110

2nd character

4th character
6th character

"n"th character

1st character

3rd character
5th character

"(n-1)"th character

"00H" indicating the end of character string

cannot be detected from the specified

device to the end device number.

b15                 b8 b7                     b0

D100
D101
D102

D7999

…

…

2nd character

4th character
6th character

00H

1st character

3rd character
5th character

13th character

"00H" indicating the

end of the character

string can be

detected.

16 bits

M115 to M100
M131 to M116
M147 to M132

M211 to M196

2nd character

4th character
6th character

"n"th character

1st character

3rd character
5th character

"(n-1)"th character

"00H" indicating the end of character string

cannot be detected from the specified

device to the end device number.

<Example 1>

16 bits

M115 to M100
M131 to M116
M147 to M132

M7679 to

M7664

2nd character

4th character
6th character
8th character

1st character

3rd character
5th character

00H

Because the data "00H" indicating the end

of the character string does not reach 16

bits, the end of the character string cannot

be recognized.

<Example 2>

16 bits

M7623 to M7608
M7639 to M7624
M7655 to M7640
M7671 to M7656
M7679 to M7672

7th character

…

…