Open Omron PLC programs without CX-Programmer
A machine arrives with its PLC program on a USB stick, a colleague sends a .cxp file, or the
laptop with CX-One is gone. Upload the project and get a printout that reads like the ladder view
of CX-Programmer: rungs drawn on the grid with the left and right bus bars, contacts, coils,
instruction boxes with one operand per line, parallel branches and output branches, the symbol
name, address and comment of every operand, rung comments, and rung and step numbers. The same
content comes as an offline HTML viewer, as the instruction list of every program, and as
symbol, comment and cross reference tables.
What to upload
| File | What it is |
|---|---|
.cxp, .bak | a CX-Programmer project or its backup, also projects with protected function blocks |
.cxt | a project saved as text from CX-Programmer |
.cxr | a CX-Programmer library file: sections, rungs or a symbol table exported from a project |
.txt | an instruction list as text, such as rungs copied out of CX-Programmer or a library file saved as text |
.zip | a zipped project folder or archive holding one of the files above |
Projects saved with CX-Programmer 9.03 to 9.82 were tested, for CP1E, CP1L, CP1H, CP2E, CJ1M,
CJ2M, CJ2H and CS1 PLCs and the older C200H and CPM1A series. The .opt file CX-Programmer saves next
to a project only holds the window layout; upload the .cxp file.
What you get
- Printout (PDF) in landscape, A4 or Letter, with a contents page and bookmarks: the project and PLC, the programs with their tasks, the units of the I/O table, every program section by section with all rungs drawn, structured text programs with line numbers, SFC charts with their steps, transitions and actions, the function blocks with their variables and bodies, the global and local symbols, data saved with the project, and a cross reference of every address and symbol.
- Viewer (HTML): one file with the program tree on the left and the drawn rungs on the right, the instruction list of each rung one click away, and a search over symbols, addresses, instructions and comments. It works offline.
- Instruction lists: a text file per program and function block in the layout of CX-Programmer's mnemonic view, with step numbers, instructions, one operand per line and the symbol name and comment of each operand.
- Tables: symbols and I/O comments, rung comments, and the cross reference as CSV, and an Excel workbook with programs, rungs, symbols, comments, function block variables, used addresses and the cross reference.
The result page shows a summary, the list of programs and the first section drawn, so you can check the file before downloading anything.
How rungs are drawn
CX-Programmer keeps each compiled rung as its instruction list (LD, AND, OR, ANDLD, ORLD, OUT,
TR0 to TR15, KEEP, CNT ...). The tool builds the ladder diagram from it the way the editor lays it
out: conditions from the left, parallel branches below each other, outputs in the right-hand
column with their comments past the right bus bar, set and reset inputs of KEEP, CNT, CNTR and
SFT as separate lines into the box. Differentiated contacts (@, %) show an arrow, immediate
refresh (!) a mark. Rungs that CX-Programmer stores as a drawing, such as function block calls
and the bodies of ladder function blocks, are drawn from that drawing. System symbols such as
P_On and P_First_Cycle show their address and meaning, for the older C-series with their
addresses there. Rung numbers start at 0 in every section and step numbers run on through the
program, as in CX-Programmer's own printout.
Only the instruction list?
If all you have is the mnemonics in a text file, one instruction per line, upload it as .txt.
Rungs separated by ^^^ lines, as in library files, are kept as they are; otherwise each rung is
found from the instructions themselves. A line starting with ' before a rung is its comment.
Without the project there are no symbol comments, so operands show as written.
Comparing two versions
Upload the older project as the CX-Programmer project and the newer one under "Second version to compare". The comparison report (PDF, HTML and Excel) lists added, removed and changed programs, sections and rungs (each changed rung drawn before and after), structured text and SFC lines, function blocks, symbols, comments, units and saved memory values.
Comments in other languages
CX-Programmer stores comments in the code page of the Windows PC the project was made on. The tool recognises Western and Central European, Cyrillic, Greek, Turkish, Baltic, Japanese, Chinese, Korean, Thai and Vietnamese text from the comments themselves. If letters still look wrong, pick the language under "More options".
What is not shown
Programs and function blocks protected in CX-Programmer are listed with their names (function blocks also with their variables), but not their content. The PLC Setup settings are not part of the printout. A file that is cut off or damaged gives a message saying so instead of a partial printout.
Privacy
Files are processed on our server only to produce your downloads, and the results are deleted automatically after 30 minutes. Program names, symbols and comments never go into our statistics.