Dear all,

I need some help with upgrading project for MCC which is controlled by CPU 315-2 PN/DP.

System temporary has some fans with star/delta starting method.

Upgrading of a system consists of implementation of VFDs with Profibus/Profinet comm options.

In order to reduce stop production time idea is to make system working with VFDs and with possibility to by-pass them in case of fault.

My question is:

what will happen if I by-pass VFDs, since downloaded HW config will have some Profibus/Profinet nodes which will be missing in that case?

And is there possibility to override possible errors and continue running the system?

Thanks,

Djap

Hello djap;

If you set the command word of the VFD to Stop, and the Speed Reference word to 0, you will not influence the motor when you bypass the VFD, and there should be no effect on the Profibus network.

However, if you feel you want to disable the VFD as a Profibusa node, you ciuld use SFC 12, "D_ACT_DP". The following link holds some hints:

Enabling a disabled DP slave with SFC 12 'D_ACT_DP'

Hope this helps,

Daniel Chartier

Dear Daniel,

Thank you for your reply. This is exactly what I need.

Thanks again.

Cheers,

Djap