A2NCPU PLC Error

[ertw 0]

Hello all, new to the forum here, but have been digging through the great detail.  Looking forward to learning from this community.

Hopefully someone here can assist with an issue i'm having with a piece of equipment running a Mitsubishi Melsac A series PLC (A62P, A2NCPU, AD57S1, AX42, AY51, AY6DS, NE21, AD76S)

Let me start with a little background.

This equipment is a Niigata brand injection molding machine. It is fairly basic in nature, is essentially a hydraulic machine w/ various valving to force cylinders. It has 2 control panels with manual functions, and a CRT with something like 5 pages. A few months back, we had a thunderstorm roll through while we were making parts. The power cut out, and when it came back, the machine HMI wouldn't turn on. Figuring we blew something up, we started to diagnose.  Ultimately, the AD57(S1) board didn't have any lights on, neither did the Ay51, AY50S or NE21.  We flipped some new boards in, with no luck.  The screen randomly comes on, but can't get the machine to turn on the motor or do anything - regardless of screen functionality.

Lately, we submitted the PLC boards to a repair shop, who said they replaced optocouplers among a few other components. We have reinstalled everything and did a hard reset on the machine.. Now i have an A2NCPU board with a constant ERROR light.

I recently purchased the RS422 cable adapter and got GX Developer working. I was able to pull the program off the PLC, and it also seems that in the "Diagnostics --> PLC Diagnostics" page, I am getting error code 13, CAN'T EXECUTE P. Reading into some of the manuals, this appears to be a program call issue?  I'm not sure how to kick the PLC into any of the programs, or rebuild the startup procedure..

Looking for someone who can assist with this. I've done a bunch with PLC over the years, but MELSEC is not one i'm familiar with.

I've attached the program for reference.. 

Thanks in advance! Happy to provide my cell number to discuss to anyone who would be willing to help. Happy holidays!

Jason

Niigata Original Program.rar

[Gambit 326]

Looks like your program is corrupted or maybe it was programmed with a GGP and not melsec medoc or GX developer . 

These PLC's are very old.

 

 

[Ron_S 61]

Yes, the whole program is corrupted.

Probably the battery failed or was removed during the repair. 

Either way, the program is lost.

[ertw 0]

Gambit, Ron, thanks for the reply --- that is kind of what I figured.  Poking around led me to a similar assumption.  What is GGP?

I'll be reaching out to Niigata to see if they will provide the original PLC program.  

If not, this thing is 12k lb of scrap!

Will let you know what i find.

[Rodney 21]

A GGP is a Mitsubishi dedicated programming terminal. They were used pre Medoc software day’s and were a step up key pad programming device. 
Like Medoc on a laptop you could monitor complete rungs.

Edited 21 Dec 2021 by Rodney

[Crossbow 295]

GPP

It looks like a giant old luggable computer, from the days before laptops.

The A Series has been obsolete for over 15 years.  There was a great migration path forward to Q Series, I remember doing many of them in the 2005-2008 timeframe.  Not sure how many of those components are still available.

[Rodney 21]

I worked on these in the early 1990s.

[ertw 0]

The equipment is 1994, but has many more years of mechanical life on it. 

Im assuming the program was written via pc, but who knows. 

Ill probably hear back from the manufacturer after the holidays!  Wish me luck. 

Thanks for the explanation 

Jason

[Crossbow 295]

Good luck, hope you can get a copy of your program.  You will then want to get a system integrator to take a look at upgrading it to a newer PLC. 

[ertw 0]

Hi All!  

Been a while since I reached out on this topic. 

I was able to purchase new EPROM chips from the supplier in Japan. I've installed them and run the process of resetting the PLC per their instructions. Of course, I have similar problems, the machine will not run, and the Error light remains on the A2NCPU board.  I plugged back in, and read the program from the PLC - and it looks better than the old corrupt version. However, the PLC diagnostics pulls up a new error code ' Missing End INS. ' 

See the pictures attached.  Not sure what to do next. My plan is to get it running, then convert to different PLC system.

When loading the program, it comes up with the first 2 images. Then I can see the End is added, but white not yellow.. I also show the PLC Diagnostics page.

Beginning to think I should just scrap the equipment alltogether. 

Thanks.

[ertw 0]

Oh, maybe it helps to toss the new file on here..

Updated Niigata program.zip

[tiagru 2]

The program looks like gibberish. Will the manufacturer not provide you the files to program the PLC yourself? If they provided you the original program, you could easily convert if for the iQ-R series.

If you the machine is fairly simple, would it not make sense to hire someone to build a new program from scratch instead of scrapping the whole thing?

Edited 5 Feb 2022 by tiagru

[ertw 0]

I've been trying to get the program from the manufacturer. But they just don't understand seemingly anything. Or they don't want to provide what I want.  Instead, they charged me $4000 for the eproms.  They were going to send a tech out, whose never seen this machine before. And had no idea how to fix it.

Unfortunately, the machine is fairly complex. Conversion to a newer plc would likely be more expensive than it is worth. 

Im going to contact them again Monday. And tell them that the eproms didn't help. 

It is strange though, that the error code changed...

[tiagru 2]

Have you considered that there may be something else damaged in the CPU module? Maybe try ordering a used CPU from eBay and installing the eproms they sold you in that CPU to see what happens?

Unfortunately, I feel your pain in dealing with equipment manufacturers. I have a few cranes that came with F940 HMIs. I had one fail on me and asked them for a replacement - they told me that they were an obsolete product and they had no replacement since that model crane had been End Of Life'd; they expected me to scrap a $500,000 crane because of an HMI. When I asked them for the program so that I could convert it and use a GOT2000, they told me that they couldn't because it was their IP.

And it seems to be getting worse. I have new crane that locks up if you change the battery with the power off. You have to either have the OEM connect to the crane via remote diagnostics or call them with a code displayed on screen and get an activation code from them. What happens if/when they decide offering support for these machines is no longer profitable?

Sorry for the rant. 

[ertw 0]

Yep. I totally agree. It's bull. You buy the machine. It should come w a copy of the software. 

I have bought numerous boards off eBay over the last year. The a2ncpu computer board was one of a stack I sent out to a company who specializes in melsec plc repairs. They said they replaced a few things inside it. I would have to pull the email and let you know what they did. 

Ill try to find it later this evening. 

The thing is.  My other 10 machines, I can call tech with an issue, and they can narrow it down to a board very quickly. Niigata seems to have no clue. Just throw parts at it.