Memory problems

[Brycam]

Hi All,

I have just installed more memory (4x32k) in my triac fanuc atc 1991 OM-b control and having backed up params and diags first I wiped all memory and restarted. Then input all the params and diags manually (could not get the comms working with 900's alone so did it the long way!) now I have 2 problems...

1, The control does not like the new memory (RAM parity error) so I am back to 10m standard.

2, More importantly, the machine will not reference, it throws up an overtravel alarm before each axis reaches the reference switch.

Any ideas? have I missed something or been a numpty?

Cheers,

Bry.

[Steve]

OVERTRAVEL on a Fanuc machine.


Parameters 700, 701 and I think 703 and 704 are the positive and negative soft limits.

When you blanked everything I think you reset the encoder count position so the machine does not know where it is.

Now when you home it the counters think the position it was in when you reset is zero.

Everytime you send it to home the machine hits the soft limit before it gets there and trips out.

you could change the overtravels valuse to 9999999 and -99999999 then home it then reset the values.

Or I am told it is posible to press P and CANCEL together then power on and the soft limits are ignored until the machine homes.

Let me know if this works as its a usefull one to highlight if it does.

[Martin]

OVERTRAVEL on a Fanuc machine.

Or I am told it is posible to press P and CANCEL together then power on and the soft limits are ignored until the machine homes.

Let me know if this works as its a usefull one to highlight if it does.

Yes,

If you power up the control while pressing in "P" & "CAN" together the control will ignore the software limits until it has been homed.

[Brycam]

Hi Steve,

P-CAN worked perfectly, thanks, nice tip!

Don't suppose you have any ideas about it not liking the memory?

[Martin]

Have you switched on the correct 900 parameters for the extra memory?

[Brycam]

I changed 901 bit 0 to 1, is that correct?

I seem to recall 912 having something to do with memory but can't remember exactly...

[Martin]

901 Bit 0 = 320M
901 Bit 1 = 120M
901 Bit 2 = 80M
901 Bit 3 = 40M
901 Bit 4 = 20M

Not sure if they all need to be set or just one

[Brycam]

That was a great help!

I set them one at a time from 20m upwards, got to 120m ok, it didnt like 320 but it can hold around 2.5k lines now.

Thanks

Bry.

[Brycam]

BTW, do you have any idea why it didn't like 320M?

I put 128k of additional memory in, thats right isnt it?

[Steve]

If you call in a Fanuc Engineer make sure you remove the memory and turn the parameter back to factory settings.

[Mr Magoo]

I think these controls had some separate smaller chips for the RAM parity BIT.
They were something like a 16 pin DIL chip next to the larger RAM chips. The existing Parity Ram chips are good upto 120M, then you need to add 2 x more to go past this limit.
There should be empty sockets on the board - put in the same chip type as the ones already on the board for the 120M Parity (they're next to the original RAM chips)

HTH

[Lone_Ranger]

BTW, do you have any idea why it didn't like 320M?

I put 128k of additional memory in, thats right isnt it?

128Kb (320 Metres) is the maximum memory for a Fanuc O (M or T) series control, that`s all the system will run, there is usually 4K available by default on the main board and 4 spaces for the 4 x 32Kb chips that you have just put in and as far as I know there is no way to get any more than that. It should actually show something a little over 126Kb available as it uses a small amount to run the system.

It`s possible that one of the chips you put in is either not properly fitted or the system doesn`t like that chip for some reason, Fanuc can be "fussy" about the SRAM it uses!!

I have an OT-C, an OT-B and an OM-Mate (F) and they are all the same.

Regards
Rob

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