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CPU 414-2 not communicating with step 7.

Created by: Rahig8 at: 1/10/2020 7:23 PM (3 Replies)

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1/10/2020 7:23 PM	Rate (0)
Rahig8 Posts: 1 Rating: (0)	CPU 414-2 not communicating with step 7. When its power on it remain on stop mode. Int+ext+bus fault shown on cpu. Checked already by complete reseting. Replaced with spare CPU worked fine but after de energized gap of 2 months, on powering up same issue happens. Again replacing Cpu issue resolved. Which factors make cpu faulty in 2 months of de energized gap.
Rahig8 Posts: 1 Rating: (0)	Last edited by: Rahig8 at: 01/10/2020 19:51:33
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1/10/2020 9:29 PM	Rate (0)
dchartier Grandmaster-Expert Joined: 9/27/2006 Last visit: 11/16/2024 Posts: 12294 Rating: (2691)	Hello Rahig8; Please tell us if there is a memory card slotted in the CPU, and if so is it a RAM card? There are 2 types if memory card you can use with a S7-400 for Load Memory, RAMand Flash EPROM. A Flash card will retain the program without battery support, but a RAM card requires that at least one functionning battery be installed in the power supply module. If the battery is missing or weak, you will lose your program when the CPU is de-energised. If this is the case, you would have the symptoms that you describe; but you could download the program to the CPU to return it to normal. Have a look at the following document for more details: How can I get an overview of the S7-400 memory concept? https://support.industry.siemens.com/cs/us/en/view/7302549 Hope this helps, Daniel Chartier

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1/12/2020 6:12 AM	Rate (0)
fariborz M Experienced Member Joined: 12/10/2018 Last visit: 6/27/2024 Posts: 109 Rating: (11)	Rahig8 CPU 414-2 not communicating with step 7. When its power on it remain on stop mode. Int+ext+bus fault shown on cpu. Checked already by complete reseting. Replaced with spare CPU worked fine but after de energized gap of 2 months, on powering up same issue happens. Again replacing Cpu issue resolved. Which factors make cpu faulty in 2 months of de energized gap. Hello dear Rahig Your CPU may need Upgrade Firmware Please Upgrade and monitor it If you want to downgrade Firmware, you can find all versions of firmware in the following link. https://support.industry.siemens.com/cs/at/de/view/109474703

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1/16/2020 9:08 AM	Rate (0)
ahmed nabil Posts: 9 Rating: (1)	Which Power supply you are using PS407 or PS405 If you are using PS 407 your 220 VAC power is through UPS or not usually if you make sure CPU's is damaged you have to revise your 220 VAC power source or change it to PS405 which use 24VDC which is more stable than 220 VAC.
ahmed nabil Posts: 9 Rating: (1)
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