[fordav11]

I'm working on an old machine with Mitsubishi Meldas 500L control. Seems to be mostly ok except one thing.
I have the operation manual which says to change to a different program press MONITOR then SEARCH, then type number and press INPUT.
It appears to work. Message says "SEARCH COMPLETED"
But the actual program that runs in the memory is not changed.
Is there some trick to selecting the program that runs in the memory?

[botha.y]

Try typing O####, then search.

[Rokkin]

Make sure you select the correct device when doing a search.

i.e. tape, memory, disk, etc

[fordav11]

I assume it's just memory. the control doesn't have a disk or tape and I don't see any way to select it either. I don't have other 'systems' either.... there isn't a $1 at the top of the screen. its a pretty basic low-end model with very few extras.

see attached page from the manual. this is the program search procedure.
at the bottom there is a O then brackets. Inside the brackets I type my program number (1234) then press input as per the instructions. The search starts and after a second or two it says 'search complete'
the O-number at the top of the screen is supposed to change to the newly searched program. but it stays on the old program.

I'm getting around this problem by editing the current program (i.e the one I'm stuck on) which contains only a M98 Pxxxx to my real program. If I want a different program I just edit the M98 program called and it works. I'm beginning to think this control is just bugged/busted?

[dblox]

Sounds like you are stuck in MDI mode.
Do you have a rotary switch with MDI, MEM, Tape, Handwheel etc on it?

[fordav11]

I'm in memory. the control panel has a single rotary mode switch with Memory, MDI and Manual and that's all. I'm doing the search with the switch in the Memory position. Like I said the search appears to work fine, just the program doesn't change.
Here's a (newer) pic of the machine..... it's a very strange beast with a manual square tool post. Don't laugh!
The control in this pic is not the same. The one I'm working on has Mitsubishi Meldas 500L but its the same machine, same model, just an older version. I have it pumping out parts so it's working fine in all other aspects. The machine belongs to a friend and I'm just helping out with programming and training but he's not so confident with even simple program editing so having proven programs in the memory and searching them would be more ideal.

[camsys]

You had posted the manual page from the Mits 500 L user manual,
and if you look at the top of that page note the "$1" field.
Does this appear on your control monitor?

This mean you have 2 part systems on the machine (aka paths or channels)
What might be happening is that you are search to load a program
into channel 2 when you're looking at channel 1 on your monitor page.

Also look at the bottom left of the screen,
When the machine has no alarms, and it's in the ready mode
you should see a header that says something like:

1 LSK (or RDY) in (or mm) G90 G40 g54 sub# fix

You must have the LSK or RDY in the first or second field, this denotes that
its in a ready state, and would be able load/reload programs.

If the fix is there then that means you have a fixed cycle in operation
(which may complicate things)

If you don't see this status then there's something up with the control
it may possibly be in an alarm state (check diag -> alarms)

At the far right on the status line you should see the current op
mode i.e. handle, memory, MDI etc...

SOme basic steps:

Push "Monitor" hard key then the POSI soft key
you should see the current prog at the top, and there s/b no subp listed
press the Monitor hardkey, and then Search soft key
make sure your in memory mode (should see the word memory at lower right)
search up your program (verify $1 - $1 on both screens search and posi)

[fordav11]

there's no $1 at the top of the screen (as I said in my post above)
I'm doing the search with Monitor hardkey and Search softkey. the program listed at the top does not change after the search is completed. I followed the method in the manual and it just doesnt work which is why I think the control may have an issue somewhere.

[camsys]

Didn't catch that $1 line in your earlier post, but that
behavior is definitely not "normal"

I don't recall if this just started happening, or was this machine
bought used. Were any macghine parameters modified or changed


How about the status line sort of at the bottom right.
Do you see RDY - In. G40 .....etc
Do you see verification on the CRT as to what mode the control is in i.e.
MDI, memory

One thing that may be at play is the memory of the control.
On older controls memory pages sometime become frazzled
for lack of a better word.

You might consider making a full backup of the system (i.e. parameters,
programs, tool offsets etc.) and going about a memory re-format.

If you're in North America, and unsure as to how to do any of the above, you can call Mitsubishi Tech Support (www. meau. com) for help. Phone support
is done for no-charge

[fordav11]

it was bought used (and abused) so condition is unknown, although it does work normally in all other functions. I've produced a few parts and it runs well.

the strange thing is I actually changed the program once. I tried it many times trying different things and just
once it changed but not sure how/why or what I did exactly. of course then I was stuck with the changed
program and I had to erase all of it and put in a M98 to my real program

apart from some rs232 settings that I adjusted, no parameters were changed. I don't know if it worked before but the guy who bought it said he talked to previous owner and said there were issues/quirks. not sure what exactly but I'm fairly sure previous owner/operator is not a skilled CNC-trained Machinist/Programmer based on the B.S. programs that were left in the machine so the issues/quirks could just be things he didn't understand or know how to do properly.

I don't want to do anything drastic like re-format memory because I can get around the problem using M98 and the re-format may turn it into a boat anchor (I'm not in the US)

I'll check the other things on-screen and post some more info in a few days when I have access to the machine again.

are there any parameters that affect the way the search works?

[fordav11]

There's something else that is puzzling me.
At the top of some of the old programs in the memory is some gibberish.
I say 'gibberish' because it doesn't conform to standard macro usage.

I don't see why someone would want to change the same macro variable multiple times without doing anything with it (i.e. #199 is set to different numbers several times). Seems to be Mitsubishi Meldas-specific?
Or the guy who programmed it was smoking some serious sh*t
Any ideas about this stuff? (see example below)

O1110( )
#195=1
#196=8001
#198=41
#199=139700
#199=3000
#199=165000
#199=-17000
#199=1200
#199=1500
#199=500
#199=50
#199=71
#199=15
#199=1
#199=1500
#199=1500
#199=40

The rest of the normal G-code program follows after this. There are
no other macro statements in the program and nothing in the program
uses the above variables.

Other programs have similar # numbers but not exactly the same answer (=xxx)

[Rokkin]

I don't want to do anything drastic like re-format memory because I can get around the problem using M98 and the re-format may turn it into a boat anchor (I'm not in the US)

Memory re-formatting will not erase machine parameters so you're safe. It will clear all machining programs, offsets, tool reg. The machine will still be operational. If you have RS-232 working, the parameters can be easily saved anyway.

[fordav11]

ok. have you got the procedure to clear memory? I don't recall seeing it in the operation manual?