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Cativo

Q12HCPU Battery issue

11 posts in this topic

Hi Everyone, New to this site, but I see lots of helpful information here. I am hoping I can learn, as well as contribute. I am currently experiencing a problem with the batter light staying on. We have replaced the battery, but the light stays on. From time-to-time I do see the light LED go out, but a day or so later it will come back on. Has anyone experienced this before? If so, what could be the problem? I attached a picture of my set up. It's on a tool here at work. Thanks for your help in advance!!! J

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The battery light does not come on an off in a day. If you replace the battery, you have to power cycle the PLC to get the light to go out. The alarm bit latches on.

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We do resets of the PLC on a regular basis and this light does not "stay" off. Shouldn't a standard reset be the same?

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Perhaps you have a broken wire on the battery holder? Or there is a hardware problem? I have not in 10 years of working with Mitsu stuff seen this issue. Put in a new battery, power cycle the CPU, error gone.

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Not sure if it is the same for all Q series P.L.C but I have done a number of Q3DU models and you have to monitor the value in SD0 enter the same value into SD50. Then turn on SM50 and then off again. The Battery light will then go off. Rodney

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Well, I am not familiar with how to check those bits, but we are scheduling time to reset this PLC unit and see if the battery light goes out. I do think it's peculiar that at times the BATT light will go out on its own and stay off for a few days. Then, one day I will walk by, and its on again. The battery I pulled out of the unit the other day reads 3.1 volts, so the battery is really not the issue (In my opinion). After leaving the new battery in the system overnight. The battery light went out. So, for now, it looks like I am OK. Peculiar!! Edited by Cativo

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Rodney, that process is for resetting any non-fatal error, not just battery. Once the low battery is detected, the light is not supposed to go out until a new battery is installed and the unit is reset. There are two battery bits, SM51 and SM52. One is a latch (like the light) and one turns itself off when the battery is good. I would monitor those two to see what's going on. Like I said, I have never seen this in over 10 years of Q Series.

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Crossbow When I first saw this I changed a battery and the battery light did not go out. So I contacted MEUK and they told me this procedure I mentioned and also if Iwas using IEC Developer there is another procedure. As I said I have done this a number of times. But I will look at the two bits you mentioned. Rodney

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Definitely peculiar. I have been monitoring the Batt LED on this unit since we installed a new battery and yet the issue remains. For three days the battery light stayed off, but on Friday the battery light was on. Today the battery light of off again. I wonder if there is something intermittently wrong with the electronics in this unit. How would I be able to dig deeper into this? We are going to be powering off the whole tool for 4 hours next week, and I don't want to lose any programs.

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My only suggestion if you have no software and cable availabe on site would be to contact your local Mitsubishi distributor and ask them for either their support or some one they could recommend to help you. Because if you loose the program it will be expensive to get up and going. Rodney .

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I would strongly recommend making a complete backup (including data register values) before powering it down for that long. This problem makes no sense to me, so perhaps you have a hardware issue. Did you check that the battery leads are not breaking off the CPU board? If it has been installed and removed several times, perhaps the wires were pulled.

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