Omron C28K problems, Emergency!!

[bluebyu]

Another possible problem is the relay outputs in the PLC. These are easy to replace if you find one bad. In your program the last 3 outputs are not being used. You use one of these if you find a bad one.

To check all outputs:
1. I would put the Plc on the bench.
2. Put the plc into program mode.
3. Force each used output on, one at a time (see page 153 in manual provided above).
4. Measure conductivity on the output being forced on.

 

[bluebyu]

If the program is valid, the inputs should all be checked.

I would suggest:
1. With Plc in press, remove output terminal strip.
2. Activate each input device and verify input comes on.
3. Watch the input led's, or put your hand held in and monitor with it.

Also, as your program is using Function 61, the High speed drum counter. Could you post the values in the PLC's memory locations DM32 through DM63 (see page 95 from the manual posted above). These values contain the ranges that the counter needs to operate.

Perhaps someone else could respond, I'm not sure since the Plc is running from a E-prom, Would those DM's be on the prom? If they are not, you have cleared those area's (as stated in previous posts)

 

[dalem]

Working from my memory of late last week. When watching the programs on line, towards the bottom of the ladder, there is a bunch of moves and multipies. I remember lots of MOV instruction which contained DM32. (Think it was shown as D0032 in the LSS program.) I only remember seeing zeros for the values. Other than a couple multiplies, which had values, like in the 1000s, the D00xx values were all zero. That did strike me as odd. (I don't see this in the program, viewing it offline from here at home. Does the program, when online with the processor, show the actual or current values to the right of the ladder diagram?)

I may or may not understand the part of the EPORM being damaged. When I put the EPROM in the bad PLC (one I need to replace), the press acts normal, with one exception, the foot input which appears to be shorted on, thus I can not inch the press. I put the same EPROM in 2 other PLCs, I get one single stroke in inch mode. Wouldn't a damaged EPROM give like symptoms in all 3 PLCs?

In inch mode, most of the machines programmed in safety features are bypassed. Two of which (I believe) are the brake monitor and I also believe the redundancy cheking that it accomplishes with the assistance of a separate Omron delay timer.

The redundancy checking with external Omron delay timer works with output 102 of the PLC pulsing the control or reset on the Omron delay timer, which in turn energises input 011 on the PLC.

The brake monitor counting prox (Input 000) should be counting 40 teeth on a cogged disk on the crank. The press is supposed to (and does) stop at about 4 teeth, after the reset prox (input 001) tells it to stop at TDC. If the crank over rotates, the brake monitor faults out and the PLC flashes one of the outputs (104, nothing wired to it), to indicate a brake monitor fault.

To initiate a stroke in single stroke mode, inputs 006, 008, 009 & 010 need to be on. I believe output 102 starts pulsing the redundance timer at the same time outputs 100 and 101 (dual solenoid valve) energises. OOPS, the stroke is initiated by energizing inputs 002 & 003. These are the 2 palm buttons, which must be made with in a few hundredths of a second of each other.

As far as In know, to make a stroke in inch mode, inputs 005, 008, 009 and 010 need to be on before pressing the palm buttons.

 

[dalem]

Just thinking out loud. I don't beleive the C28K PLC can burn anything to the EPROM chip. When the press is powered down, does the PLC store any parameters or info in RAM even though it boots from EPROM? If such is the case, is it possible that the press MFG preloads some data into some of the RAM area so that when the PLC boots from EPROM, some of the blanks are filled in from RAM or other data areas. I knew FUN61 pertains to the brake monitor prox which is supposed to monitor 40 teeth in some manner. I didn't see anything when online which lead me to think I found the program comparing the HS counter prox (000) to a 40 tooth sprocket or such that the crank stops aprox 4 teeth past the reset prox (001).

If I haven't mentioned it in a while, thanks again for any and all assistance.

Dale

 

[elevmike]

dalem,

Go back and download the manual and check your dip switch settings. One of the dips are for using a high speed counter (I think). I'm not sure that this will resolve the issue, but check it. We have a power outage today so I havent had a chance to look at your code, and have to get back to that later.

Back to the grill..

 

[bluebyu]

The installation guide has the info on the dip switch setting

http://forum.mrplc.com/index.php?act=Downloads&CODE=02&id=390

Your program indicates a software reset for the high speed counter, this should require dip switch's 7 + 8 to be off (you indicated earlier that is how they were set).

You are correct, the C28K, alone cannot burn the Eprom. A seperate piece of hardware is required, a C500-PRW06.

I think that the Eprom contains your program, however when you swapped PLC's, the program came into the new PLC when you switched the Eprom. The values that are stored in DM32 through DM63 are still in the original PLC (as long as the battery is ok) Try hooking up the old plc and down loading the dm area, than down load the dm area to your good plc.

The HDM (function 61) needs these values to set up the windows for when to turn all 17.XX bits (your program is using 10 outputs in word 17, all turned on by the high speed counter when it gets to certain counts)

Take a look at your program at any word 17 bit. ie: 17.00 or 17.01, there is no coil the turn the bits on and off, they are turned off by the high speed counter function.

Hope this helps.

Mark

 

[dalem]

Blue and Elev, thanks for the ideas and suggestions. I'm back in today and will be looking into some things here, soon. The press is running now with the bad PLC, so I have to work around them now. I have had the manuals that that have been suggested and have looked through them, perhaps too long, bu thave not found the solution myself doing such. What sparked the idea that the press mfg sent that first replacement to us years ago, only requiring the EPROM swap and possibly having some info preloaded into the unit was comments in the programming manual which states the DM TM and HR areas data is retains at power outages. (or something like that.) I'll look into my LSS program and see where/how to download the data (DM) areas, then see if I can dump them into one of these spares that has the program D/L into it, then desk simulate operation. Previously, all attempts to simulate operation with the PLC set up on my desk have previously failed, but then again all attempts to put these spares into the machine have also failed.

I must have mistyped something in a reply to this thread about having dip switch settings for 7&8 being set. The mfg info and PLC in use has always been set to 00110100. Only in the spare units, where I tried running the program from ram did I change those dip sw settings to 11000100.

 

[dalem]

Elevmike,

Just curious if there's something aviation related going on there? If so, perhaps the screen name I used over at MrPLC forums, which is c150L, might mean something to you.


Dale

 

[dalem]

BINGO!!!!!

I hope... Went out, transfered the DM data to my old lappy and found lots of values that do not show up in the program backups I did from the EPROM unit. Went up and set up my desk testing PLC, transfered the ladder and DM data in the original PLC and am able to inch the PLC and get the dual solenoid valve outputs to energise. Also can simulate the single stroke mode, but it soon faults out due to the redundancy checks being missing. (Not simulating that.) I also get a brake monitor fault in inch mode because I'm not simulating the 000 input pulses as it would see on the press. I did this simulation on both spares and have good/favorable results on both spares. Both running from RAM.

ASAP, I'm going to install one of these spares into the press and see how it goes there. I will keep you alll posted on how that goes.

One other thing. Any reason I would prefer setting up to run from the EPROM VS running from RAM?

Thanks again for all the suggestions and/or ideas. Hope I can return the favor one day.

Dale

 

[bluebyu]

If your battery should die, you would loose your program. E-prom eliminates that potential. However, since the designer of you program choose not to move all required DM values into memory at the PLC startup, the Eprom is not really helping you. The Eprom has a secondary benifit of making it harder to change the program. You have a mature plc program that works well, if the program was not in E-prom, changes would get made to the program to "fix" something else that went wrong.

All the C28K's I have running use Ram. Even using Ram, when values are required in DM's to make the program function, whenever I can, on the first scan of the Plc, I use the "Mov" function to set the value into ram.

ie: Mov #147 DM32
Mov #239 DM33 etc

Most of the Omron software requires you to download the program into the Plc, and than download DM's into the plc if Dm's are required, and if the Plc does not write the values.

Good luck

 

[elevmike]

Ok so ive finally found my Omron stuff, some of it anyway, but for the life of me cant remember the keystorkes to load the program code. It's been more then 5 years. Does anybody have the manual for LSS2?

 

[Jay Anthony]

Try here:

http://forum.mrplc.com/index.php?act=Downloads&CODE=02&id=511

 

[dalem]

LSS2? Is that still a DOS based program or something more Windows based? Like the mouse is useful for something.

 

[bluebyu]

You may want to purchase Syswin from Omron. I'm not sure if your dealer still sells it, but you can also purchase it on E-Bay. Syswin is windows software, as LSS is not. The newest Omron software, CX Programmer (CX1) does not support the C28K series.

 

[elevmike]

dalem,

LSS2 is DOS, no mouse. I'd thought it would be like riding a bike, but apparently not & I have to re-edumakate myself. Sorry for the delay, but it's really busy here so I'll look get to it after work.

Jay, thanks for the link. I thought I had put all the OMRON stuff togeather, but the LSS2 manual is missing.