adccommunitymod (AutomationDirect) asked a question.
using a backup battery
Created Date: May 23,2008
Created By: a agnone
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How do you set the DL250-1 to use the low battery light and SP43? In the book it says to set V7633 and set bit 12. I did. I see in data view bit 12 is on. I pulled the battery out, powered down first than took out the battery, powered up and the Batt light nor SP43 changed. I tried to leave the plc powered up and opened the battery slot, but again no change on Batt light. What am I doing wrong.
Created Date: May 23,2008
Created by: KPrice
a agnone, I do not believe you are doing anything wrong. I believe the battery must be installed for the BATT LED to turn on when the battery voltage drops below the 2.5VDC, when bit 12 is set. So with no battery, you will not get a BATT LED, (or battery backup of course).
Created Date: May 23,2008
Created by: a agnone
KPrice, I do not get the light! When I pull the battery out, the light never comes on and the SP43 they talk about is still says off. I will try a DL240 and see what happens.
Created Date: May 23,2008
Created by: marksji
agnone, the SP43 contact and battery light will be on for a battery voltage of more than 0v and less than 2.5v. If the battery voltage is more than 2.6v or 0v (ie removed) then neither the battery light nor SP43 will come on.
At least that's how I understand it... I 've never actually made it work either.
Created Date: May 23,2008
Created by: Glenn
Actually, the battery does not need to be inserted.
Try entering a BCD value of 1000, or Decimal 4096, just in case you got the bit thing mixed up.
Created Date: May 23,2008
Created by: a agnone
Glenn I entered bcd 1000 with no battery and it worked. That is with the DL 240 CPU. It does not work with the DL-250-1. I suppose no one uses the feature, so AD is not aware or it now working. I just wanted to use it because we started putting in batteries in the machines. With out them, after weeks of sitting not powered up, they go out of run mode. I was going to display "Battery Low " on the C-More. But it looks like I will not be able to do that. Little confused with what Glenn told me to do and the light comes on without a batter installed, whereas Mark says there is a range that the light comes on, being 0V (no batt) the light should have not come on, but it did. Maybe the CPU's react differently. I will discharge a batt to nearly 2v and see what happens. This has become a quest. The need to understand. Simply problems excite me.
Created Date: May 23,2008
Created by: marksji
Please post what you find as I'd love to know.
I can tell you that at some point, many years ago, how the low battery function works in the 250 CPU was changed (firmware update). Since that time we have never managed to nail down what is supposed to happen when and frankly we just stopped trying.
Created Date: May 23,2008
Created by: KPrice
Learn something new every day. a agnone, like you, I tested a 240 and it worked, BATT LED came on with no battery and bit 12 set in V7633. Also, I tested a 260 and an old 250, and they also worked, BATT LEDs came on. Unfortunately, I don't have a 250-1 here to test.
Created Date: May 24,2008
Created by: a agnone
I feel so stupid. I tried it on a DL260 and it worked. It works on the DL-250-1. When I did the DL260, there was no battery in the slot. What I did with the DL250-1 was I just opened the slot, thinking the battery connection was broken. I had to physically remove the battery. It works on all. I feel so dump.
Created Date: May 23,2008
Created by: a agnone
How do you set the DL250-1 to use the low battery light and SP43? In the book it says to set V7633 and set bit 12. I did. I see in data view bit 12 is on. I pulled the battery out, powered down first than took out the battery, powered up and the Batt light nor SP43 changed. I tried to leave the plc powered up and opened the battery slot, but again no change on Batt light. What am I doing wrong.