Easy 512-AC-RC - Program automatically goes into STOP mode

[sazzyboy]

Please help? I have a PLC which is programmed up to control motors manually and automatically via one of the internal time clocks and inputs . A problem has occured where the PLC will go into STOP mode itself and therfore not function. Obviously the first thing i have checked is wether there is retention. If you power off the PLC and turn it back on again the program loads and runs as it should. The program is password protected and the end user does not know it. What I would like to know is there any way to put the PLC into STOP mode without using the password. I have tried everything but failed. I have checked the program written to see if I have made a mistake and as far as I can see there is nothing obviously wrong. I have tried several PLCs thinking it was a faulty one and it only seem to happen in this application. The program is used in other applications and is working fine. Is it me or the end user? Many thanks to anyone who could help me solve this problem.

[KressSwiss]

Hi
Not so easy to find a reason. What about the electromagnetic environment (EMC) around the PLC? Are dere frecuency converters or other devices like this neareby? According your statement it could be a EMC problem.
Regards Hermann

[sazzyboy]

Yes we do have a DF51-322-0.37 frequency Inverter in the same enclosure, but this application has been used many times without a problem till now. I have recently spoken to someone that says it could be a spike in the electrical supply? Could this enable the PLC to change to STOP mode and is there a way to prevent it?. Many thanks for your help.

[sazzyboy]

Just to add, if it was a spike in the supply to the PLC that makes it go into STOP mode would fitting a memory module to the PLC stop this from happening?

[KressSwiss]

if it was a spike in the supply to the PLC that makes it go into STOP mode......

May be. But I'm not really sure.

But an other thing....

Frequency converters are the most problematical devices connected with ESD. A clean wiring with screened cables and electrostatic filters are requisite.   
I was told of unofficial source that EASY with operating system 05 are less sensitiv of ESD then older systems. In fact of the frequency converters in your application it could be useful to change the devise against a device with newest operating system.  You can find the operating system version on the left side of the housing.  This is a not official information and there is no guarantee of success. But it can not be wrong to change the unit.

Regards and lot of sucecc
Hemann


 

[sazzyboy]

many thanks, somebody else suggested filters and some sort of suppression but without knowing the voltage and frequency of the spike its hard to tell. I have the exact application on different sites and this is the only one with a problem. So i would say it is not related to the DF51. Trial and error from now on. many thanks.

[KressSwiss]

Hi
There is a "assortment help slider" for supressor-devices on the Moeller Homepage. You can find there the superssor-equippmenf for Moeller frequency converter DF51.

http://www.moeller.net/de/support/slider/frequenzumrichter.jsp