Hello All,

We have recently developed an automation system with Siemens CPU 315-2 PN/DP as the core processor along with 7 other I/O modules. Coding was done using TIA Portal V13 and system was working fine for almost 02 months. 

After the lapse of 02 months, we have received call from user stating that PLC is not working. Here is how is is behaving at the moment:

1) Power supply is workign correctly and giving exact 24 V DC on output

2) DC 5V LED is ON (Yellow) continuously after power up

3) STOP LED (Yellow) is continuously blinking with 0.5 Hz flashing

4) All LEDs are OFF

5) CPU is not interfacing with TIA portal software (not getting detected), with or without MMC.

6) We have changed the CPU and plugged in the new CPU with same MMC and it started working fine.

7) The faulty CPU is not even connecting with software without any other I/O connected and same STOP LED keeps on blinking.

8) We have tried MEMRES operation but no success.

Please help me in this problem, We cant afford new processor at the moment in our project. Since this card was bought in 2016, warranty period is also void. Please help. Thans

hi hafeezqazi,

have you tried to set ist in factory settings?

have a look in following manual how to do it, chapter 9.5:

SIMATIC S7-300 CPU 31xC and CPU 31x: Installation

also check the firmware, if there is a newer version. In the firmware-update-notes you find informations about the changes of the newer firmware.

Operating System Updates for CPU 315-2 PN/DP (6ES7315-2EH14-0AB0)

hope this helps,

regards,

Hi,

MMC seems to be OK - do a factory reset like our friend mpS04 proposed. If this will not work you should consider, that´s there is a defect.

Regards,

Towome

Tried factory reset, all indication went correct. However, after factory reset response of CPU is still same.

Firmware is already updated. Am i having issued with hardware?

Please help!

mopS04

hi hafeezqazi,

have you tried to set ist in factory settings?

have a look in following manual how to do it, chapter 9.5:

SIMATIC S7-300 CPU 31xC and CPU 31x: Installation

also check the firmware, if there is a newer version. In the firmware-update-notes you find informations about the changes of the newer firmware.

Operating System Updates for CPU 315-2 PN/DP (6ES7315-2EH14-0AB0)

hope this helps,

regards,

 Tried factory reset, all indication went correct. However, after factory reset response of CPU is still same.

Firmware is already updated. Am i having issued with hardware?

Please help!