S7-400 cpu led status

[gdalianis]

Hi,

does anyone knows what is the problem on an S7-400 cpu in case all the leds are constantly on (not blinking, I think in this case it that the cpu is defective).

Thank you

 

[SHKODRAN]

Are you able to communicate with plc ?

 

[keithkyll]

Check power supply.

 

[gdalianis]

Check power supply.

I have a 6ES7 405-0RA00-0AA0 power unit and is this is power supplied by another psu 220 to 24V 37A. Both the leds 24V and 5V leds on the power unit is green as well as the 5V led on the IM 461-1 on the second rack. I also suspect that is possible that I have a problem on the initial power supply unit, is there a way to check it? Also at the power supply unis the indicator BAF is red with BA1F been orange. I tried to connect to the PLC. Allthought the step 7 is tryning to make the connection the cpu comes out grey at the end...
Please I am desperate to start the system and I still can not find what is source of the problem, any help would be highly aprecciated...

 

[Purrdie]

Before this occured, did you turn off the PLC? Then when you turn it on all LED is lit up and the BAF, and your program is not running anymore. I suspect that your PLC program was erased.

Change the PS battery and redownload the program. Make sure that before you turn off the PLC power supply, the BAF LED is not lit.

 

[gdalianis]

Before this occured, did you turn off the PLC? Then when you turn it on all LED is lit up and the BAF, and your program is not running anymore. I suspect that your PLC program was erased.

Change the PS battery and redownload the program. Make sure that before you turn off the PLC power supply, the BAF LED is not lit.

still no luck after replacing the batteries and eliminate the BAF on the power supply. The status of the leds of the cpu is the same and I can not connect to it with the pc.....

 

[KalleOlsen]

Try to reset the CPU with the MRES and the exercise with the RUN/STOP button. Leave the button in STOP position, and try to connect with the PC before you try to RUN.

Eventually also do a power cycle with the button kept in STOP.

Btw, is it a RAM or a Flash memory card sitting there?

Kalle

 

[gdalianis]

Try to reset the CPU with the MRES and the exercise with the RUN/STOP button. Leave the button in STOP position, and try to connect with the PC before you try to RUN.

Eventually also do a power cycle with the button kept in STOP.

Btw, is it a RAM or a Flash memory card sitting there?

Kalle

Still no luck. I read the manual of the PLC to reset with MRES, but the led status at the CPU does not change according to the intructions of the manual. I can not connect to the CPU at all with my PC, even at the switch at stop. No additional card is installed at the CPU...

 

[osmanmom]

http://www.plctalk.net/qanda/showthread.php?t=48744


S7-400 Automation System, CPU Specifications
Manual, 10/2006, 6ES7498-8AA04-8BA0

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