Applicability Of Programming Languages In Programming Software; Compatibility Among Programs - Mitsubishi Electric FX3G SERIES Programming Manual

FX /FX /FX Series Programmable Controllers
3G 3U 3UC
Programming Manual - Basic & Applied Instruction Edition
4. ST (structured text)
The ST language is a text language with a similar grammatical structure to the C language.
1) Features
The ST language can describe control achieved by syntax using selective branches with conditional statements
and repetition by repetitive statements in the same way as high-level languages such as the C language.
By using the ST language, you can create simple programs that are easy to understand.
5. Structured ladder
The structured ladder language is a graphic language for writing programs using ladder symbols such as
contact, coils, functions, and function blocks.
1) Features
The structured ladder language is a graphic language developed based on the relay ladder programming
technique.
Since it can be understood intuitively, it is commonly used for the sequence programming.
A circuit always starts from the bus line located on the left side.
6. FBD (Function Block Diagram)
The FBD (function block diagram) language is a graphic language for writing programs using parts for special
processing (functions and function blocks), variables and constants.
1) Features
You can create programs easily by connecting parts along the flow of data and signals, and improve the
programming efficiency.
1.1.2

Applicability of programming languages in programming software

The table below shows the applicability of programming languages in GX Works2 and GX Developer:
Applicability in GX Works2 and GX Developer
Programming Language
List programming
Circuit programming
SFC programming
ST
Structured ladder/FBD
1.1.3

Compatibility among programs

All sequence programs created by list programming, circuit programming or SFC programming are stored in the form
of instruction words (contents at the time of list programming) in the program memory inside the PLC.
• Programs created by these three types of input methods can be converted mutually, and then displayed and edited
as shown in the figure below.
Circuit
It is not possible to display or edit sequence programs created using ST, structured ladder or FBD programming by
converting them from the form of instruction words (contents at the time of list programming).
For displaying and editing such sequence programs using ST, structured ladder or FBD programming, the symbolic
information (data indicating the program configuration such as structure and labels) is required.
→ Refer to the GX Works2 Version 1 Operating Manual (Common) for the details on symbolic information.
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GX Works2
List
SFC
GX Developer
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1.1 Programming Language in PLCs
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1 Introduction