DL-06 Program Retention

[pstephens]

Hi!

I'm in the process of compiling a spare parts list for the customer who recently had me design the Pin Installation Machine. (Thanks again for all the help!)

They are big on keeping major replacement parts on hand to minimize downtime. What I'm wondering: Is there a way to store a DL-06 PLC, with the program pre-loaded, such that the program will be retained for an extended period without external power? I know that the battery is designed to maintain the system RAM when the power is off, and the "super-capacitor" has discharged, but will the program be retained as long as the battery is viable? Or is there another way I'm not aware of?

Any suggestions much appreciated.

Paula

 

[icky812]

The program will be retained "forever". The ladder itself is stored in FLASH memory so unless the PLC is subjected to high voltage or other extreme conditions the program should not just "go away".

So basically if you are not using the system RAM to store setpoints then you really don't need to have a battery in it during storage. Even if you do have a battery, the RAM should be retained for years usually. The actual amount time the battery lasts of course will be deteremined by how and where the PLC is stored (temp, humidity, etc...)

 

[pstephens]

Thanks, Icky, I didn't know that! This is a fairly simple sequence-type program, and the only "setpoints" would be the timer values. It sounds like this is less of a problem than I was making it.

Paula

 

[MarkTTU]

Something I do with all my software is have a set of factory defaults for all the variables (timer values, counter values, etc). For factory defaults you don't have to be perfect, just safe.

For example, if V2000 is a timer preset and I know that the value should be something around 5 seconds then I'll have a rung that looks like this:

-SP0--V2000=K0-------------LD k50
				OUT V2000

 

[pstephens]

Thanks for the tip, Mark!

Paula

 

[elevmike]

Store your preset variables in NVram. The DL06 has 124 NVram locations. this will allow you to store variables without a battery. Keep in mind that you can only write to NVram so many times.

Here's a link on how NVram works. http://support.automationdirect.com/docs/nonvolatilememory.pdf

Apparently this document was authored before the DL-06 was introduced, but I would assume it applies none the less.