Mitsubishi Electric MELSEC iQ-F Series User manual

MELSEC iQ-F Character String Operation
Function Block Library Reference

1
SAFETY PRECAUTIONS
(Read these precautions before use.)
Before using this product, please read this manual and the relevant manuals introduced in this manual carefully and pay full
attention to safety in order to handle the product correctly.
This manual classifies the safety precautions into two categories: [ WARNING] and [ CAUTION].
Depending on the circumstances, procedures indicated by [ CAUTION] may also cause severe injury.
It is important to follow all precautions for personal safety.
Store this manual in a safe place so that it can be read whenever necessary. Always forward it to the end user.
WARNING Indicates that incorrect handling may cause hazardous conditions, resulting in
death or severe injury.
CAUTION Indicates that incorrect handling may cause hazardous conditions, resulting in
minor or moderate injury or property damage.

2
INTRODUCTION
Thank you for purchasing the Mitsubishi Electric MELSEC iQ-F series programmable controllers.
This manual describes the module function blocks for the target modules listed below.
It should be read and understood before attempting to install or use the module function blocks.
Always forward it to the end user.
Target module
• FX5S CPU module
• FX5UJ CPU module
• FX5U CPU module
• FX5UC CPU module
Regarding use of this product
• This product has been manufactured as a general-purpose part for general industries, and has not been designed or
manufactured to be incorporated in a device or system used in purposes related to human life.
• Before using the product for special purposes such as nuclear power, electric power, aerospace, medicine or passenger
movement vehicles, consult Mitsubishi Electric.
• This product has been manufactured under strict quality control. However when installing the product where major
accidents or losses could occur if the product fails, install appropriate backup or failsafe functions in the system.
Note
• If in doubt at any stage during the installation of the product, always consult a professional electrical engineer who is
qualified and trained in the local and national standards. If in doubt about the operation or use, please consult the nearest
Mitsubishi Electric representative.
• Since the examples indicated by this manual, technical bulletin, catalog, etc. are used as a reference, please use it after
confirming the function and safety of the equipment and system. Mitsubishi Electric will accept no responsibility for actual
use of the product based on these illustrative examples.
• This manual content, specification etc. may be changed, without a notice, for improvement.
• The information in this manual has been carefully checked and is believed to be accurate; however, if you notice a doubtful
point, an error, etc., please consult your local Mitsubishi Electric representative. When doing so, please provide the manual
number given at the end of this manual.

3
CONTENTS
CONTENTS
SAFETY PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
INTRODUCTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
RELEVANT MANUALS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
TERMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
GENERIC TERMS AND ABBREVIATIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
CHAPTER 1 OVERVIEW 5
1.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.2 List of FB Libraries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.3 System Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
CHAPTER 2 SPECIFICATIONS 7
2.1 FB Library Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.2 List of Structures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.3 Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
CHAPTER 3 DETAILS OF FB LIBRARIES 10
3.1 M+StrProcessing_JSONDeserialize_F (Acquisition of JSON String). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Labels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Function details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Parameter settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Performance values. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Error code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.2 M+StrProcessing_JSONSerialize_F (Construction of JSON String) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Labels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Function details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Parameter settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Performance values. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Error code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
CHAPTER 4 APPLICATION EXAMPLE 22
4.1 Acquiring Value String from JSON String. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Process flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Programming. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
4.2 Constructing the JSON String . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Process flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Programming. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
INSTRUCTION INDEX 29
REVISIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
TRADEMARKS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32

4
RELEVANT MANUALS
TERMS
Unless otherwise specified, this manual uses the following terms.
GENERIC TERMS AND ABBREVIATIONS
Unless otherwise specified, this manual uses the following generic terms and abbreviations.
Manual name Description
MELSEC iQ-F FX5S/FX5UJ/FX5U/FX5UC User's Manual (Hardware)
<SH-082452ENG>
Hardware of the CPU module, including I/O specifications, wiring, installation, and
maintenance
MELSEC iQ-F FX5 User's Manual (Application)
<JY997D55401>
Basic knowledge about programming, functions of the CPU module, devices/labels,
and parameter settings
MELSEC iQ-F FX5 Programming Manual (Program Design)
<JY997D55701>
Program specifications (ladder, ST, FBD/LD, and SFC programs) and labels
MELSEC iQ-F FX5 Programming Manual (Instructions, Standard
Functions/Function Blocks)
<JY997D55801>
Specifications of the instructions and functions that can be used in programs
GX Works3 Operating Manual
<SH-081215ENG>
Explanation of system configuration, parameter settings, and online operations of GX
Works3
Term Description
Engineering tool A tool used for setting up programmable controllers, programming, debugging, and maintenance
JSON string Data string based on the way JavaScript objects are written
Key string Value for identifying the Value string in the JSON string
Member Structure including the type, Key string, Value string, and depth of hierarchy
Value string Data to be written after the Key string in the JSON string
Generic term/abbreviation Description
FB An abbreviation for "Function Block". A function block is created from a ladder block repeatedly used in a sequence
program so that it can be used as a component in a sequence program.
Using FBs helps to develop programs more efficiently, reduce mistakes, and improve quality of programs.
FX5 A generic term for FX5S, FX5UJ, FX5U, and FX5UC programmable controllers
FX5 CPU module A generic term for FX5S CPU module, FX5UJ CPU module, FX5U CPU module, and FX5UC CPU module
FX5S CPU module A generic term for FX5S-30MR/ES, FX5S-40MR/ES, FX5S-60MR/ES, FX5S-80MR/ES, FX5S-30MT/ES, FX5S-40MT/
ES, FX5S-60MT/ES, FX5S-80MT/ES, FX5S-30MT/ESS, FX5S-40MT/ESS, FX5S-60MT/ESS, and FX5S-80MT/ESS
FX5U CPU module A generic term for FX5U-32MR/ES, FX5U-32MT/ES, FX5U-32MT/ESS, FX5U-64MR/ES, FX5U-64MT/ES, FX5U-64MT/
ESS, FX5U-80MR/ES, FX5U-80MT/ES, FX5U-80MT/ESS, FX5U-32MR/DS, FX5U-32MT/DS, FX5U-32MT/DSS, FX5U-
64MR/DS, FX5U-64MT/DS, FX5U-64MT/DSS, FX5U-80MR/DS, FX5U-80MT/DS, and FX5U-80MT/DSS
FX5UC CPU module A generic term for FX5UC-32MT/D, FX5UC-32MT/DSS, FX5UC-64MT/D, FX5UC-64MT/DSS, FX5UC-96MT/D,
FX5UC-96MT/DSS, FX5UC-32MT/DS-TS, and FX5UC-32MT/DSS-TS
FX5UJ CPU module A generic term for FX5UJ-24MR/ES, FX5UJ-24MT/ES, FX5UJ-24MT/ESS, FX5UJ-40MR/ES, FX5UJ-40MT/ES,
FX5UJ-40MT/ESS, FX5UJ-60MR/ES, FX5UJ-60MT/ES, and FX5UJ-60MT/ESS

1 OVERVIEW
1.1 Features 5
1
1OVERVIEW
The function blocks in this reference manual mean the FB libraries for character string operation in the MELSEC iQ-F series.
1.1 Features
This section describes the features of this function.
Shortening programming time
Programming time can be shortened because the character string operation program that had to be created by combining
instructions for CPU modules is grouped into blocks for each function.
1.2 List of FB Libraries
The following table lists the FB libraries in this reference manual.
: Required, : Not required
For these FB libraries and software, please consult your local Mitsubishi Electric representative.
For the FB library registration method, refer to the following.
GX Works3 Operating Manual
1.3 System Configuration
The following figures show examples of system configuration for using the FB libraries in this reference manual.
Name Description Parameter
setting
M+StrProcessing_JSONDeserialize_F (Acquisition of JSON
string)
Acquires the Value string corresponding to the specified Key string from the
JSON string.

M+StrProcessing_JSONSerialize_F (Construction of JSON
string)
Constructs the JSON string by specifying the Key string and Value string. 
(1) Programmable controller programmed by
using the FB libraries
FX5S, FX5UJ, FX5U, or FX5UC CPU module
(2) Personal computer where GX Works3 is
installed
(1) (2)
Ethernet
(1)

61 OVERVIEW
1.3 System Configuration
MEMO

2 SPECIFICATIONS
2.1 FB Library Specifications 7
2
2SPECIFICATIONS
This chapter describes the common specifications of the FB libraries in this reference manual.
2.1 FB Library Specifications
The FB libraries in this reference manual are used on a single CPU module of the MELSEC iQ-F series without
communicating with external devices.
For the available number of characters and character codes, refer to the following.
Page 10 DETAILS OF FB LIBRARIES

82 SPECIFICATIONS
2.2 List of Structures
2.2 List of Structures
The following table lists the structure used in the FB libraries in this reference manual.
Member
It is the structure used for constructing or acquiring the JSON string.
Set uDepth (depth of hierarchy) of pb_st30Member, which is the structure used in the FB libraries, according to the following
rules.
• The initial value of hierarchy is 1.
• The Value string parenthesized with {} indicates an object.
• If the Value is an object, one following hierarchy increases.
• When the end of an object is reached, one following hierarchy decreases.
In the JSON string below, hierarchies are surrounded by solid lines and objects are surrounded by dotted lines.
Name Description
Member Refers to member information.
Label Label name Data type Setting range Description
uType Type of Value Word [unsigned]/bit string [16 bits] 0 to 4 Set the type of Value.
0: Member structure array end
1: Object
2: Array
3: String
4: Numerical value/true/false/null
s32Key Key string String (32) 31 characters + a
terminator
Set the Key string and terminator.
s64Value Value string String (64) 63 characters + a
terminator
■When it is used in the JSON string acquisition
FB
Used to store the acquired Value strings. No
setting is required.
■When it is used in the JSON string construction
FB
Set the Value string and terminator.
uDepth Depth of hierarchy Word [unsigned]/bit string [16 bits] 1 to 30 Set the depth of Key hierarchy.
{
”name”: ”taro”,
”age”: 29,
”image”: {
”visible”: true,
”Title”: ”View from 15th Floor”,
”Thumbnail”: {
”Url”: ”http://www.example.com”,
”Height”: 125,
”Width”: 100
} ,
”IDs”: [116,943, 234, 38793]
}
}
Object
Hierarchy 1
Hierarchy 2
Hierarchy 3
Hierarchy 2

2 SPECIFICATIONS
2.3 Precautions 9
2
2.3 Precautions
Before using the FB libraries in this reference manual, check the following precautions.
Description
The FBs in this reference manual do not include the error recovery processing. Prepare the error recovery processing separately to suit the user's system and
the expected operation.
Do not use the FBs in programs that are executed only once, such as a subroutine program or FOR-NEXT loop, because i_bEN (execution command) cannot
be turned off and the normal operation cannot be acquired. Always use the FBs in programs that can turn off the execution command.
The FBs require the configuration of a ladder block for every input label.
The FBs cannot be used in an interrupt program.

10 3 DETAILS OF FB LIBRARIES
3.1 M+StrProcessing_JSONDeserialize_F (Acquisition of JSON String)
3DETAILS OF FB LIBRARIES
3.1 M+StrProcessing_JSONDeserialize_F (Acquisition
of JSON String)
Overview
This FB acquires the Value string corresponding to the specified Key string from the JSON string.
Labels
Input labels
*1 The setting range differs depending on the "Device/Label Memory Area Setting" in "CPU Parameter".
Output labels
Public variable (input)
No. Label Name Data type Import Setting range Description
(1) i_bEN Execution
command
Bit Always On, Off On: FB starts.
Off: FB does not start.
(2) i_udJsonAddr JSON start
address
Double word [unsigned] At start of
FB
Valid device
range*1
Specify the start address of the file register
where the JSON string is stored.
No. Label Name Data type Default value Description
(3) o_bENO Execution status Bit Off On: The execution command is on.
Off: The execution command is off.
(4) o_bOK Normal completion Bit Off The on state indicates that the FB has been
completed successfully.
(5) o_bErr Error completion Bit Off The on state indicates that an error has
occurred in the FB.
(6) o_uErrId Error code Word [unsigned]/bit string [16
bits]
0 The error code of an error that occurred in the
FB is stored.
(7) o_uValueNum Number of Value
strings that have
been acquired
Word [unsigned]/bit string [16
bits]
0 The number of Value strings that have been
acquired is stored.
No. Label Name Data type Setting range Description
(8) pb_st30Member Member list Member (0..29) Specify the member information related to
acquisition.
For details on the structure, refer to the
following.
Page 8 List of Structures
o_uErrId:UW
o_bErr:B
o_bOK:B
o_bENO:B
UD:i_udJSONAddr
B:i_bEN
(1) (3)
(4)
(5)
(6)
(2)
M+StrProcessing_JSONDeserialize_F
o_uValueNum:UW (7)
(8)pb_st30Member

3 DETAILS OF FB LIBRARIES
3.1 M+StrProcessing_JSONDeserialize_F (Acquisition of JSON String) 11
3
Function details
Applicable hardware and software
Basic specifications
Function description
• Turning i_bEN (execution command) on searches for s32Key (Key string) of pb_st30Member (member list) in the JSON
string and acquires the corresponding Value string. Refer to the following for the procedure to acquire the Value string from
the JSON string.
Page 12 Usage procedure
• In the FB, the JSON string is converted to the same format as pb_st30Member (member list) and analyzed. More than 30
members result in error completion, causing an error (202H) to occur. (Page 12 Usage procedure)
• After all Value strings corresponding to s32Key (Key string) specified in pb_st30Member (member list) have been acquired,
o_bOK (normal completion) turns on.
• If an error occurs during acquisition of the Value string, o_bErr (error completion) turns on and processing of the FB is
interrupted. In addition, an error code is stored in o_uErrId (error code). (Page 15 Error code)
Module Firmware version Engineering tool
FX5S CPU module 1.00 or later GX Works3 Version 1.087R or later
FX5UJ CPU module 1.032 or later GX Works3 Version 1.087R or later
FX5U/FX5UC CPU module 1.271 or later GX Works3 Version 1.087R or later
Item Description
Language to use Ladder
Number of steps 3232 steps
The number of steps of the FB embedded in a program depends on the CPU module used, the input/output definitions,
and the option setting of GX Works3. For the option setting of GX Works3, refer to the following.
GX Works3 Operating Manual
Points of labels used • Label: 8824 (Word)
• Latch Label: 0 (Word)
The points of labels embedded in a program depend on the CPU module used, the devices specified for arguments, and
the option setting of GX Works3. For the option setting of GX Works3, refer to the following.
GX Works3 Operating Manual
Points of index register used • Index register: 1 point, Number of the device used (Z9)
• Long index register: 0 points
When using an interrupt program, do not use this index register in the interrupt program.
Points of file register used 0 points
FB dependency No dependency
FB compilation method Subroutine type
FB operation Pulse execution type (multiple scan execution type)

12 3 DETAILS OF FB LIBRARIES
3.1 M+StrProcessing_JSONDeserialize_F (Acquisition of JSON String)
Usage procedure
The following shows the procedure to acquire the Value string from the JSON string.
1. Regarding the JSON string for acquisition, set uType (type of Value), s32Key (Key string), and uDepth (depth of
hierarchy) for items to acquire the Value string in pb_st30Member (member list).
• Configure settings other than s64Value (Value string) in pb_st30Member (member list).
• If the number of members is less than 30, set "0" to uType (type of Value) in pb_st30Member (member list) that is acquired
last.
Ex.
2. After i_bEN (execution command) is turned on, the Value string whose uType (type of Value), s32Key (Key string), and
uDepth (depth of hierarchy) completely match those specified in pb_st30Member (member list) is acquired.
Ex.
{
”id”: 1,
”name”: ”userA”,
”attribute”: {
”gender”: ”male”,
”nationality”: ”japan”
},
}
”phonenumber”: 8022224568
1
2
3
4
5
0id
name
attribute
gender
nationality
Not specified Not specified Not specified
1
1
1
2
2
3 (string)
3 (string)
1 (object)
3 (string)
0 (member structure array end)
4 (numerical value)
Array
element No.
uType s32Key uDepths64Value
pb_st30Member (member list)
Do not specify the values
of s64Value.
JSON string for acquisition
Searching Key Searching value
Array
element No.
uType s32Key uDepths64Value
1
2
3
4
5
0id
name
attribute
gender
nationality
Not specified Not specified
1
1
1
2
2
3 (string)
3 (string)
1 (object)
3 (string)
0 (member structure array end)
4 (numerical value) 1
userA
NULL
male
japan
The searched values are stored in s64Value.
pb_st30Member (member list)
Not specified

3 DETAILS OF FB LIBRARIES
3.1 M+StrProcessing_JSONDeserialize_F (Acquisition of JSON String) 13
3
Timing chart of I/O signals
■Completed successfully
■Completed with an error
0
OFF
i_bEN
o_bENO
pb_st30Member
o_bErr
o_uErrId
o_bOK
(execution command)
(execution status)
Acquisition status
(member list)
(error completion)
(error code)
(normal completion)
Unexecuted Executing Unexecuted
Initial state …
Acquisition
result 2
Acquisition
result 1
Acquisition result n
i_bEN
o_bENO
pb_st30Member
o_bErr
o_uErrId
o_bOK
0 0
OFF
(execution command)
(execution status)
Acquisition status
(member list)
(error completion)
(error code)
(normal completion)
Error code
Unexecuted
Initial state

14 3 DETAILS OF FB LIBRARIES
3.1 M+StrProcessing_JSONDeserialize_F (Acquisition of JSON String)
Precautions
• Only the Value string whose uType (type of Value), s32Key (Key string), and uDepth (depth of hierarchy) completely match
those specified in pb_st30Member (member list) is acquired. Partially matched strings are not acquired.
• Special characters including escape sequences are not supported. A Value string including any special character may not
be acquired correctly. The JSON string supports 0x00 and 0x20 to 0x7E.
• "true", "false", and "null" are identified only by their first character. For numerical values, e, +, -, and the position and
number of periods are not checked.
• When the target Value string has 64 characters or more, 63 characters from the beginning are stored.
• If the target Value string is not found or is an object (pb_st30Member.uType (type of Value in member list) is K1), NULL is
stored in s64Value (Value string) of pb_st30Member (member list).
• Even if uType (type of Value) of pb_st30Member (member list) is K1 (Object), configure the settings for s32Key (Key string)
and uDepth (depth of hierarchy) of pb_st30Member (member list) because of influence on search results of this FB.
• Set pb_st30Member (member list) according to the JSON string sequence. Otherwise, the Value string may not be
acquired correctly.
• Store a NULL-terminated ASCstring in the Key string.
• Any string with the multidimensional array or nested array is not acquired.
• Any independent JSON string (array, string, numerical value, true, false, null) constructed only with the following strings is
not supported.
Parameter settings
Parameter settings are not required for this FB.
Performance values
*1 When the program capacity is set to 128K steps, the processing speed may become slow.
*2 The standard area is used for labels.
Input type Example
Array alone [1, "a"]
String alone "ab"
Numerical value alone 2
Boolean value alone true
Null alone null
Module Measurement condition Processing time Maximum scan time Number of scans
Number of
members
Number of
characters in
JSON string
FX5S CPU module 1 100 837.000ms 21.800ms 37 scans
15 1000 1670.000ms 24.500ms 97 scans
30 16383 64100.000ms 70.500ms 1123 scans
FX5UJ CPU module 1 100 708.000ms 18.400ms 37 scans
15 1000 1440.000ms 21.200ms 97 scans
30 16383 59900.000ms 64.500ms 1123 scans
FX5U/FX5UC CPU
module*1*2
1 100 586.000ms 15.200ms 37 scans
15 1000 1190.000ms 17.900ms 97 scans
30 16383 50800.000ms 55.400ms 1123 scans

3 DETAILS OF FB LIBRARIES
3.1 M+StrProcessing_JSONDeserialize_F (Acquisition of JSON String) 15
3
Error code
*1 Output only for one scan.
Error code Description Action
100H The setting value of i_udJsonAddr (JSON start address) exceeds
the maximum value of file register.
Check and correct the setting, then execute the FB again.
101H The setting value of uType (type of Value) of pb_st30Member
(member list) is out of range.
A value other than 0 to 4 is set for the type of Value.
Check and correct the setting, then execute the FB again.
102H The setting value of uDepth (depth of hierarchy) of pb_st30Member
(member list) is out of range.
A value other than 1 to 30 is set for the depth of hierarchy.
Check and correct the setting, then execute the FB again.
103H The number of characters in s32Key (Key string) of
pb_st30Member (member list) is out of range.
Unintended memory in the CPU may be accessed.
Set s32Key (Key string) using 31 characters or less.
200H i_bEN (execution command) is turned off during processing. i_bEN (execution command) must be on until normal completion or
error completion turns on.*1
201H A JSON string that is not available in this FB is stored. Correct the target JSON string, then execute the FB again.
202H The number of members of JSON string exceeds 30. Correct the target JSON string, then execute the FB again.

16 3 DETAILS OF FB LIBRARIES
3.2 M+StrProcessing_JSONSerialize_F (Construction of JSON String)
3.2 M+StrProcessing_JSONSerialize_F (Construction
of JSON String)
Overview
This FB constructs the JSON string by specifying the Key string and Value string.
Labels
Input labels
*1 The setting range differs depending on the "Device/Label Memory Area Setting" in "CPU Parameter".
Output labels
Public variable (input)
No. Label Name Data type Import Setting range Description
(1) i_bEN Execution
command
Bit Always On, Off On: FB starts.
Off: FB does not start.
(2) i_udJSONAddr Start address of
JSON string
storage location
Double word [unsigned] At start of
FB
Valid device
range*1
Specify the start address of the file register
where the constructed JSON string is
stored.
No. Label Name Data type Default value Description
(3) o_bENO Execution status Bit Off On: The execution command is on.
Off: The execution command is off.
(4) o_bOK Normal completion Bit Off The on state indicates that the FB has been
completed successfully.
(5) o_bErr Error completion Bit Off The on state indicates that an error has
occurred in the FB.
(6) o_uErrId Error code Word [unsigned]/bit string [16
bits]
0 The error code of an error that occurred in the
FB is stored.
(7) o_uJSONLength Number of
characters in
JSON string
Word [unsigned]/bit string [16
bits]
0 The number of characters (bytes) in the
constructed JSON string is stored.
No. Label Name Data type Setting range Description
(8) pb_st30Member Member list Member (0..29) Specify the member information about the Key
to be constructed.
For details on the structure, refer to the
following.
Page 8 List of Structures
o_uErrId:UW
o_bErr:B
o_bOK:B
o_bENO:B
UD:i_udJSONAddr
B:i_bEN
(1) (3)
(4)
(5)
(6)
(2)
M+StrProcessing_JSONSerialize_F
o_uJSONLength:UW (7)
(8)pb_st30Member

3 DETAILS OF FB LIBRARIES
3.2 M+StrProcessing_JSONSerialize_F (Construction of JSON String) 17
3
Function details
Applicable hardware and software
Basic specifications
Function description
• A JSON string is written using the format of {"Key string (item)": Value string (value)}.
• Turning i_bEN (execution command) on constructs the JSON string by using the Key string (item) and Value string (value),
and stores the JSON string in the file register. Refer to the following to construct the JSON string.
Page 18 Usage procedure
• After the JSON string has been output, o_bOK (normal completion) turns on.
• If an error occurs during construction of the JSON string, o_bErr (error completion) turns on and processing of the FB is
interrupted. In addition, an error code is stored in o_uErrId (error code). (Page 21 Error code)
Module Firmware version Engineering tool
FX5S CPU module 1.00 or later GX Works3 Version 1.087R or later
FX5UJ CPU module 1.030 or later GX Works3 Version 1.087R or later
FX5U/FX5UC CPU module 1.270 or later GX Works3 Version 1.087R or later
Item Description
Language to use Ladder
Number of steps 2681 steps
The number of steps of the FB embedded in a program depends on the CPU module used, the input/output definitions,
and the option setting of GX Works3. For the option setting of GX Works3, refer to the following.
GX Works3 Operating Manual
Points of labels used • Label: 10472 (Word)
• Latch Label: 0 (Word)
The points of labels embedded in a program depend on the CPU module used, the devices specified for arguments, and
the option setting of GX Works3. For the option setting of GX Works3, refer to the following.
GX Works3 Operating Manual
Points of index register used • Index register: 1 point, Number of the device used (Z9)
• Long index register: 0 points
When using an interrupt program, do not use this index register in the interrupt program.
Points of file register used 0 points
FB dependency No dependency
FB compilation method Subroutine type
FB operation Pulse execution type (multiple scan execution type)

18 3 DETAILS OF FB LIBRARIES
3.2 M+StrProcessing_JSONSerialize_F (Construction of JSON String)
Usage procedure
The following shows the procedure to construct the JSON string by using the Value string (value).
1. Set a numerical value corresponding to the type of Value string (value) for the JSON string to be constructed in uType
(type of Value) of pb_st30Member (member list). The type of Value string is as follows. 4: Numerical value/true/false/null,
3: String, 2: Array, 1: Object, or 0: Member structure array end.
2. Set the Key string (item) for the JSON string to be constructed to the s32Key (Key string) of pb_st30Member (member
list).
3. Set the Value string (string, numerical value, array, boolean value, null) that pairs with the Key string (item) for the JSON
string to be constructed to s64Value (Value string) of pb_st30Member (member list) as a string. If uType (type of Value)
of pb_st30Member (member list) is an object, s64Value (Value string) of pb_st30Member (member list) does not need to
be set.
4. Set uDepth (depth of hierarchy) of pb_st30Member (member list) according to the rules described in the following.
Page 8 List of Structures
5. If the number of members of pb_st30Member (member list) is less than 30, set "0" in uType of the last array element
number.
6. Set the start address of the file register where the constructed JSON string is stored in i_udJSONAddr (start address of
JSON string storage location).
Ex.
*1 If uType is an object, the values of s64Value do not need to be set.
{
”id”: 1,
”name”: ”userA”,
”attribute”: {
”hobby”: [2, ”running”,
”swimming”],
”nationality”: null
},
}
1
2
3
4
5
0id
name
attribute
hobby
nationality
Not specified Not specified Not specified
1
1
1
2
2
1
userA
NULL
2, ”running”, ”swimming”
null
2 (array)
3 (string)
1 (object)
4(null)
0 (member structure array end)
4 (numerical value)
Array
element No.
uType s32Key uDepths64Value*1
JSON string to be constructed
Key to be constructed Value to be constructed
pb_st30Member (member list)