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CPU313C "frozen" analog inputs + all LED flashing

Created by: fmb at: 11/14/2011 10:07 PM (13 Replies)

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11/14/2011 10:07 PM	Rate (0)
fmb Member Joined: 5/24/2006 Last visit: 7/16/2025 Posts: 5 Rating: (0)	I have a system based on a CPU313C using V2.6.11 where sometimes the values of thefive CPU313C integrated analog inputs become "frozen" and it is necessary to power OFF/ON. In addition, in the same system sometimes the CPU goes in the state "All LED flashing"; after power OFF/ON and STOP->RUN it works again for an irregular time (sometimes short time, sometimes longer) and then the problem happens again... I have changed CPU but without success. Do you think these two problems could be related?

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11/16/2011 12:52 PM	Rate (0)
Marko Bursic Platinum Member Joined: 9/8/2009 Last visit: 7/17/2023 Posts: 1410 Rating: (154)	I have experienced all led flashing in compact type cpu if you remove some integrated module from it. I guess something wrong is with your analog module, maybe its on board power supply or something is burned. you should talk with your siemens dealer if its worth to repair it, with my experience the repair cost is just some bucks less than new cpu.

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11/19/2011 11:00 AM	Rate (0)
fmb Member Joined: 5/24/2006 Last visit: 7/16/2025 Posts: 5 Rating: (0)	Hi Marko,Thanks for your answer.In my case, in this moment I would be oriented to exclude that the only cause is a CPU 313C faulty because I have changed it (with no success) and, moreover, in my case if I power OFF/ON the system, it works good for some time (in case of faulty modules or modules not properly connected I think the problem should appear immediately and should block the system). The cause of my problem seems a temporary effect: it causes the “defective” status in the CPU but after this it disappear, and appear again after some time… When the problem happened to you, you changed the CPU and the problem disappeared?

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11/19/2011 5:21 PM	Rate (0)
Marko Bursic Platinum Member Joined: 9/8/2009 Last visit: 7/17/2023 Posts: 1410 Rating: (154)	No , I didn't change the cpu, my inputs were frozen, also analogic outputs didn't work, but I had another compact cpu and I have exchanged analog cards. I asked for repair, but was more than new analog module, so I have installed new analog module on rack and rewired, because I wanted analog card back. Then I thougt that might be a good idea to leave card place empty, since it was burned but then cpu flashed with all leds. So I put the burned card back into cpu, apparently is still alive but only analog part is burned. Its very difficult o understand, you are right if is burned then it would flash all time from begining, more weird is that you changed cpu and you get the same. First of all check wiring, my module burned because I used it with devices, that were all galvanicaly isolated and the potential of analog part was floating, I should connect MANA to ground to give a potential to analog loop. Maybe your module picks up a noise from some high frequency generator that zaps a cpu of analog module and stops working.

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11/21/2011 10:33 AM	Rate (0)
Darius Platinum Expert Joined: 9/28/2005 Last visit: 7/24/2025 Posts: 2957 Rating: (243)	Hi, What information do you see in diagnostic buffer ?
	Best regards, Darius
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11/22/2011 2:01 PM	Rate (0)
Jazz_M Gold Member Joined: 9/6/2008 Last visit: 5/7/2022 Posts: 1121 Rating: (86)	Hi Well check the earthing for you panel is proper, I once had the same problem, the panel earth and the system earth was joined and given to MCC earth. so there was leakeage of 110 V across the panel. if your earthing is not proper then such type of problem shall come. Check the leakage between neutral and earth, points. It should be less than 5 V apporximate. Have fun...
	Jazz
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11/22/2011 10:15 PM	Rate (0)
fmb Member Joined: 5/24/2006 Last visit: 7/16/2025 Posts: 5 Rating: (0)	Darius Hi, What information do you see in diagnostic buffer ? In the diagnostic buffer I have always found this: DEFECTIVE : internal system error No relevance for user (Z1): da01 Previous operating mode: RUN Requested operation mode: DEFECTIVE Internal error, Incoming event

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11/22/2011 10:43 PM	Rate (0)
Marko Bursic Platinum Member Joined: 9/8/2009 Last visit: 7/17/2023 Posts: 1410 Rating: (154)	I feel sorry, but yo will have to contact your Siemens dealer and/or click go on mySupport pageand write this code, they are only one who can tell you what is going on. I had similar diag. buffer one time and I had to replace cpu, they told me cpu or mmc is gone. Do you have same DC motor brakes, big solenoid valves or coils? They can induce high voltage spikes and destroy electronic parts.

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11/23/2011 6:39 AM	Rate (0)
Jazz_M Gold Member Joined: 9/6/2008 Last visit: 5/7/2022 Posts: 1121 Rating: (86)	fmb Darius Hi, What information do you see in diagnostic buffer ? In the diagnostic buffer I have always found this: DEFECTIVE : internal system error No relevance for user (Z1): da01 Previous operating mode: RUN Requested operation mode: DEFECTIVE Internal error, Incoming event Hi well it seems that your CPU is defective, try changing the CPU and check, if there is a MMC card try removing that and check if the same error is comming. Or try upgrading your firmware of your CPU. If nothing works get in touch with your local siemens support they will be able to help you. Have fun...
	Jazz
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11/23/2011 9:47 PM	Rate (0)
fmb Member Joined: 5/24/2006 Last visit: 7/16/2025 Posts: 5 Rating: (0)	Tagolover fmb Darius Hi, What information do you see in diagnostic buffer ? In the diagnostic buffer I have always found this: DEFECTIVE : internal system error No relevance for user (Z1): da01 Previous operating mode: RUN Requested operation mode: DEFECTIVE Internal error, Incoming event Hi well it seems that your CPU is defective, try changing the CPU and check, if there is a MMC card try removing that and check if the same error is comming. Or try upgrading your firmware of your CPU. If nothing works get in touch with your local siemens support they will be able to help you. Have fun... I have already replaced CPU andMMC with no success :-( Concerning the firmware,I use the latest (2.6.11). My next planwould be trying to replace the power supply and the other SM 3xx modules connected to the CPU (n.1 AI8, n.1 DI32, n.1 DI16, n.2 DO32 and n.1 DO16). In case the problem comes frommy machinery(the machinery controlled by the PLC) and in case I don't find where is the origin of the "bad signal", I would like to find something that could prevent the CPU to beaffected by this "bad signal".. Do you think it could be a good idea touse two power supplies and to divide CPU+DI supplies from DO supplies?

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