When release the reset signal the drive goes to the error 421

Hi, I have same issue. I tried using MC_reset block. When I press enable , the error goes (checking in the configuration window in TIAv15.1) When I release the reset signal, the drive again goes to the error 421 and error message is Disable. 

I checked in PLC , it shows this error 

can someone guide me on this error.

I am posting in this feed just to avoid making a new question. 

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Split from MC Alarm 421.

Hi Nico,

What you are describing doesn't sound exactly correct, maybe I am misinterpreting you.

The MC_RESET instruction uses an execute type command, which means only a rising edge is recognized by the block so setting the input to low should not do anything, except make the outputs of the block invalid. Just because the "Done" output of the MC_RESET goes high after a rising edge at the "execute" input, it does not mean that the technology object is now enabled, it just means that the MC_Reset command was execute successfully, however if the fault is still present it will not allow the technology object to be re-enabled. 

The behavior I believe you are describing is that when you set the "execute" input to MC_Reset to low the "Done" output of MC_Reset is also going low. This is because the outputs of the block are only valid while the execute input is high.

In my experience MC 421 is most commonly to do with safety functions in the drive being enabled. Make sure the safety functions are disabled before giving rising edge to the "execute" input of MC_Reset. I have also however had MC 421 pop up when the drive has not being responding, make sure the network is configured and working properly.

Are you using safety features? Do you also see MC 550 alongside MC 421?

Regards

Hi,

I agree seancarey,

Probably your safety function (e.g. STO) is still active when you do the MC_Reset, so the routine would be to deselect the function and then put a rising edge to MC_Reset.

Hi Seancarey,

what i mean is that when I press reset button the error goes away until the drive is reset, on the drive return to normal state it again gives me the error. I know it has nothing to do with MC_rest block.

I also check the safety features in drive, they all are disable as I am not using safety in this project. 

I also observed that when my software limits are reached and i still try to push the drive over software limit, it gives me this error (421) 

But in your first post it sounded that you cannot move your drive at all?!

So you can switch it on and move it? And then for any reason you get fault 421 during operation?

Which drive do you use exactly?

Hi, I am using S110 with CU305PN

Yes sometime it just stops working and there is a red led (ready led) flashing on Control unit. 

I can power off the unit and then power it up again and it will work.