ControlLogix plc crashes

Ron the bon · May 9, 2006

Hi everybody,

I am using 3 L-55 processors on 3 differents racks. All of them are connected each other with ethernet. All of them have a separed DeviceNet network.
I am using RS Logix5000 version 15.00.

Here my problem: last week 2 processors crashed, the battery were empties (I replaced them end of January 2006!!!!) and the processors were empty too

. Then I downloaded the program again and until now is working good.

Some ideas?

RonTheBon

Oakley · May 9, 2006

There is a tech note on the L55 and battery life.
Essentially there is a design flaw on the L55 that allows the processor to quickly drain the battery - approx 1 hour without power. The fix was to upgrade to the BATM battery or change the processor to the L6x.

Some fix.

John M · May 9, 2006

I haven't seen that tech note. Could you point me to it or post it?
We have lots of L55 controllers to support and that would be something we need to consider.

Ron the bon · May 9, 2006

Hi John,

Do you have the same problem as I have?

Vic · May 9, 2006

The battery life is not as short as Oakley says. There is a table on page 42 of the Controllogix Selection Guide which gives the worst case battery life for different memory modules. Battery life is from 13 to 63 days.

I do not know of a design flaw which drains the battery in hours. The L6x series B controllers have much better battery life.

John M · May 9, 2006

Ron,
I don't have your problem but I was spooked by the thought of batteries draining in an hour. I have never seen it. I have only seen what Vic posted which is more reasonable.

wildswing · May 9, 2006

Oakley, can you provide a link to this tech note please? I can't find it.

olias · May 9, 2006

I had an L55 in the field that would kill the battery every couple of weeks and then lose the program.I had to install a BATM battery. I'm now using L61 Series B on all new machines which has a Flash memory card that will store all the memory on shutdown.Then the battery turns off. Rockwell says the battery will last for years. BATM is about $100 where as the L61 is about $3000. Your choice.

akreel · May 9, 2006

olias said:
I'm now using L61 Series B on all new machines which has a Flash memory card that will store all the memory on shutdown.

How are you making it do that? I've only seen the "save to NVRAM" options available when you're online.

Are you sure that your most recent set points are being saved?

Contr_Conn · May 9, 2006

L6x ser B does not need Compact Flash card to save program on power down.

L6x ser B has internal NVRAM that used to save RAM data while powering down using battery.
After save is done processor does not use battery at all - this extends battery life.
On the power up processor checks internal NVRAM - if image is valid - it will copy it back to the RAM.

No setting needed to use it.

akreel · May 9, 2006

Contr_Conn said:
L6x ser B does not need Compact Flash card to save program on power down.

L6x ser B has internal NVRAM that used to save RAM data while powering down using battery.
After save is done processor does not use battery at all - this extends battery life.
On the power up processor checks internal NVRAM - if image is valid - it will copy it back to the RAM.

No setting needed to use it.

Well, this sure is interesting!

What gets saved? Program, data, or both?

I played with some L63s and compact flash. It would save set points at the time I did the NVRAM dump. Then on power-up (if selected) the CPU would boot off the Compact Flash with the old data.

With the series B firmware, is there a way to save the program and data to NVRAM in its last state automatically? Does it require compact flash?

Contr_Conn · May 9, 2006

What gets saved? Program, data, or both?

Both.

I played with some L63s and compact flash. It would save set points at the time I did the NVRAM dump. Then on power-up (if selected) the CPU would boot off the Compact Flash with the old data.

Compact flash will act like this in both ser A and ser B hardware

With the series B firmware, is there a way to save the program and data to NVRAM in its last state automatically? Does it require compact flash?

This is not ser B firmware, this is ser B hardware, Ser B processor actually have internal NVRAM chip. It will save all RAM if battery is good at shutdown. Don't need Compact Flash card

If battery is bad during shutdown, nothing will be saved. But battry life is dramatically increased as it is not used while processor is off.

Contr_Conn · May 9, 2006

Everything I said above is for ser B processor only. It has nothing to do with Compact Flash card.

Now how to save current data from the ladder to the Compact Flash card?

A little history:
Ver 13 Firmware introduced this feature in 2004.
But in 2005 this application was removed due to possible data corruption.
New application currently is available from techsupport for L6x processors with ver 15.4 firmware only.
Compactlogix firmware will be available soon.

What it does, is actually adds support for the FAT16 file system used with CF cards. Application can create, delete, read and write file to CF. So technically user can save data from the ladder program on the fly. But don't try to write every scan, CF card life is only 300,000 write cycles - usually much more.

kamenges · May 9, 2006

Originally posted by Contr_Conn:

L6x ser B has internal NVRAM that used to save RAM data while powering down using battery.

So why didn't they just add several hundred more microfarads of capacitance across the power bus in the processor and get rid of the battery completely? The battery just seems like a weak link in an otherwise solid system.

Keith

Vic · May 9, 2006

Contr_Conn

Are you sure of your information? The information about the nonvolatile memory in the ControlLogix User Manual says that the L6x controllers use Compact Flash and you must manually save any changes to the nvram. I have copied this section below:

ControlLogix plc crashes

Ron the bon

Member

Oakley

Member

John M

Member

Ron the bon

Member

Vic

Member

John M

Member

wildswing

Member

olias

Member

akreel

Member

Contr_Conn

Member

akreel

Member

Contr_Conn

Member

Contr_Conn

Member

kamenges

Member

Vic

Member

Similar Topics