Mitsubishi

Hi. I have a downloaded program from a Mitsubishi FX0N24MT processor. See attached zipped file. The programming software is GX-Developer-FX. There are various contact throughout the program that have no associated coil ie M438. I can see M438 change state as the machine runs (The HMI is not connected) but I cannot find where or how it is switched. Also 2 inputs X0 and X2 do not appear in the ladder though they are wired in and from what I can tell they are needed.
Will this model support other languages that cannot be uploaded by this software so therfore I only see the ladder and not the fuction block code.
To everyone that has to use Mitsubishi in their daily lives I offer you my sincere condolences.
Regards Alan Case

I've had a quick look. It seems that in some places data register values are being written to M coils.

For example look at line 735. Where it says MOV D22 K4M160 that will write the value of data register 22 to M160 thru M165 in binary. Therefore any one of those M coils could change state depending on what D22 is doing.(I've no idea what it does, I haven't looked in that much detail!)

I've an idea that the inputs that are connected but don't seem to be in the program may be something to do with high speed counter. Others more familiar with FX may be able to confirm this.

Edit. The contact is M348 not M438.
OK, thanks Potter, that make sense but I cant find anywhere where the contact M348 around rung marker 1364 is altered. There are no coils, moves or double moves that affect this contact.
Regards Alan Case

Rung 1300 is some kind of shift instruction, I suspect it could be something to do with this.

Alan, just having a quick look at it

The inputs that are wired to X0 X1 X2 are high speed count inputs and these are counting on Line 0 Counter No's C235 C236 C237 (although the last 2 are set to zero. (The inputs Xo etc do not show in the logic when used for HSC)

Will get back with more when I have had a look

EDIT indeed potter is right - the shift left instruction is causing these bits to turn on. (at line 1300)

That line means when m104 and m100 are true record the state of M102 and shift it one place (K1)to the left starting at M200 for a stack of 200 M bits (K200) so M200 to M399 are the shift pattern bits

Thanks. It is making a bit more sense now.
Regards Alan Case

First off thanks to those that have helped me on this project, this rant is no reflection on you guys but the more I study the Mitsubishi software the more antiquated and arcane I find it. The manuals are very basic, ie the move instruction is detailed as "Moves data from one storage area to another storage area" Well that is stating the bleeding obvious. No examples of what controls the length of the move, the source or the destination. You can move a counter (a value) to an M bit. You can also prefix the destination M Bit with a constant ie K4M0. No expanation in the manual what this means.

With all the special relays you have to trawl through the manual to find what they mean then comment them yourself. No such thing as visible word wrap in the comment editor. This is an 80s style interface. Windows copy and paste is not supported either.

Still cant find where and even if you can have rung comments. The search function cannot find any item if it is not in text in the program. ie a bitshift of 5 items starting at M0 will not find M1, M2 etc.

It is a real battle to program with this and I can see why Mitsubishi has such a small market share here.
Regards Alan Case

It is a real battle to program with this and I can see why Mitsubishi has such a small market share here.

Click to expand...

I feel your pain.
Had a piece of OEM equipment come in from Taiwan last year with a "dog's breakfast" collection of control gear. Mitsi FX plc, Proface HMI, Parker servo motors and drives, Baldor Mint motion controller, Fuji VFD.

That Mitsi s/w sure is ugly, but the Proface stuff is near incomprehensible.

Since we had to make additions and needed on-line access for commissioning (both serial ports on the FX were used) we junked everything but the Parker gear and installed CLX and PV+. The Fuji drive didn't matter but was an orphan so was replaced by site standard ABB. Made a few enhancements in the process.

Alan
for rung comments just click on the rung. Enter a semicolon, this will open a box. You have to leave the semicolon there, just type your comment and hit enter. If it doesnt show up goto View and put checkmark by Statement.
Im right with ya on the manuals.
Bob

Hi Bob. A semicolon brings me up a "Find" window.
Regards Alan Case

Found it.
You need to be in edit mode to add rung comments but you can be in read mode to add comments to the bits.
What a pile of ****

Perhaps a poll should be started

Worst PLC Software

I too find the GX world awful...........

Lol, we are all allowed a rant - especially at unfamiliar software.


This week I was using some unfarmiliar Panasonic software for their PLC's and when I tried to connect to the PLC it said 'connecting to PLC please wait a while' Those are the exact words - 10 minutes later and it still had not connected, I wondered what 'a while' meant.

We just acquired a job to document a Mitsubishi program. I heartily agree with the sentiments here. If anyone finds a manual, website, etc. with some basic help to program an A2 processor with GX Dev software I would be greatly appreciative!!!

You need a copy of the Mitsubishi common instructions book. It is extremely helpful and is a downloadable as a pdf. I will return with the link tomorrow.

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