Battery on Vision series

[VFU1076]

Hey folks, 

This question was probably answered, but i am going to ask one more time as i could not find the answer. 

I have been using V700 controllers in my projects and have gone through some issues in regard to the battery. It goes flat and as you must know I lose my data at power-off. 

I added some code on my program where I am using the SB8 bit to detect when the battery is weak so that way my customer knows the battery needs to be replaced to avoid losing the data at power-off.

As far as I know, the controller uses a volatile (RAM) memory and non-volatile (Flash) memory which saves my data once the controller is powered off. 

My question is, 

Is the battery used while the controller is powered up? or is it only used when the controllers is turned off ?

 

Thank you in advance.

[Flex727]

I've been wondering about this question also. While I haven't done any formal testing, I believe the battery is only used when the 24V power is removed from the PLC. If the PLC remains powered up 24/7 (as it was built to do) then the battery will last at least 8-10 years (depending on how fresh the battery was when installed). If the PLC is powered off for extended periods of time, the battery life appears shorter. I always include SB8 notification in my projects.

You're probably aware that you can download the project into flash memory so that it doesn't depend on the battery.

[Flex727]

Here is a small article I just stumbled upon, though it's not very helpful for this specific topic.

https://support.unitronics.com/index.php?/selfhelp/view-article/unitronics-plcs-battery-models-and-expected-life

[Simon]

To add a related point, if it is safe to access the PLC with the power on, and the battery cover is accessible (no snap in module installed) then you can replace the battery without powering down the PLC.  While the PLC has 24VDC power, the battery is not required for retaining data. 

Simon

[Flex727]

7 minutes ago, Simon said:

you can replace the battery without powering down the PLC

This is true, but sadly it is necessary to reboot the PLC in order to reset SB 8.

[VFU1076]

Hey @Flex727and @Simon, i really appreciate your reply. 

Yes, I am aware of the procedure regarding the replacement of the battery. I have created a help menu on my screen where i guide my customer on how the battery needs to replaced as well as its specs. Controller must be powered while the battery is being replaced and then a power cycle to reset SB8. 

 @Flex727, you mentioned above that the project can be downloaded into flash memory, so i usually create a clone file and save it on a SD card so i always have a backup. However, my customers are forgetting to replace the battery and then when it goes totally flat they lose their application at power-off.  I need to guide them to go in info mode and restore the application from the SD card. 

I do not know if there's any other way to do this. 

 

[Flex727]

11 hours ago, VFU1076 said:

I do not know if there's any other way to do this. 

"Download All & Burn" when downloading the project will save the project to flash memory and thus it won't be lost when the battery goes flat. However, if you have configuration settings that are stored in operands, those will be lost. However, you can save and restore operands (or application, clone, etc) from ladder and place a button on the screen to restore those (or even do it automatically when the program starts).

[VFU1076]

Sounds good, Flex727.  I've never done that before, but will check this out.  I usually use the option "Upload All & Burn" so i can upload the application in the future in case there's no backup. 

Your saying that if the battery goes flat and the controller is powered off, i can restore my application from ladder through a button on screen? The controller shows the  info mode screen when that happens and the application needs to be backed up first from the SD so is it possible to back this up through a button on the screen instead?

 

 

[Ausman]

2 hours ago, VFU1076 said:

I usually use the option "Upload All & Burn"

There's a bit of upload/download confusion here.  Unitronics refers to things in a different way to most.  What you are using I guess is Download All & Burn, what Flex suggests, which shouldn't be giving the program loss you are referring to.  Flex has covered all the bases.

I suggest that you play with "battery flat" scenarios yourself to find the actual results.  On renewing the battery you shouldn't need to do anything, unless modified (from Initialisation settings) operands are in use.  

2 hours ago, VFU1076 said:

The controller shows the  info mode screen when that happens and the application needs to be backed up first from the SD

As I only use 130s, this might be a quirk of V700s I'm unfamiliar with.  However, I feel sure that there is a way around this "requirement" that you are missing.  That's the whole point of Download all and Burn.  It's onboard.

cheers, Aus

[Flex727]

7 hours ago, VFU1076 said:

Your saying that if the battery goes flat and the controller is powered off, i can restore my application from ladder through a button on screen?

No. I am saying that if you "Download All & Burn", your application will still be there when the PLC is powered back on. Have you ever noticed that there is a (very simple) program running in a brand-new PLC and there is no battery installed? That program was placed there at the factory with "Download All & Burn".

What I was saying about a button on the screen is that all the SD functions relating to saving and restoring the program are available in ladder. That includes clone files, application, operands, etc. My suggestion was to burn the program so that is not lost, but if you have Operand values that are important and could be lost, you could include a ladder function to save and restore those values if needed. Obviously if the program was not "burned" then ladder function to restore the program will not be helpful as that would be lost.

[VFU1076]

thanks for clarifying. I will check this out and play with a V700 i have here in stock. 

 

 

[Simon]

The "Burn Upload Project" option should also burn the project to flash so it isn't lost if the battery goes flat.  Try doing a test with the battery removed.

[kratmel]

One more tips...

If settings of machine is placed to Data table - part of project - it saved to flash and it is possible place  default value for all operands via menu activated by ONE button.

 

[Jeff164]

On 10/26/2021 at 7:13 PM, Flex727 said:

This is true, but sadly it is necessary to reboot the PLC in order to reset SB 8.

I just now discovered this.   I'm scratching my head as to why.... but if this is the case it answers my question.  

i  had included an SB-8 bit to trigger an alarm to notify the customer's staff to replace the battery.   In testing the system - the alarm functioned but I could not get it to reset without a power cycle.   

I do a final burn on of the code all my machines prior to shipment, but as I undersand it this should save the code and graphics but any parameters that the end user may have set up will be lost without the battery.    

Is there a way we can enquire to Unitronics why we need a power cycle to reset SB-8?  

 

thanks Flex !

[Flex727]

1 hour ago, Jeff164 said:

any parameters that the end user may have set up will be lost without the battery.    

I'm not sure why this is a problem. Change the battery without removing power then reset the PLC. 24V power never needs to be removed from the PLC at any time during the process. Even if you feel the need to power cycle the PLC after changing the battery you won't lose operand values.

SB 300 can be used to reboot the PLC from the HMI screen without disrupting power also.

[Jeff164]

Thanks much - I’ll look into SB 300.  
 

Its not that its much a problem to power cycle- but knowing my typical customers- if I can make that part of the alarm circuit self-reset after they press an acknowledgment button it could alleviate a support phone call.