When any of the fatal errors take place, PLC controller stops operating and all outputs are shut down. PLC controller cannot be put back to work until the controller is turned off and then turned back on, or until it is switched to PROGRAM mode via peripheral device and the fatal error corrected.
With these errors, indicators ERR/ALM are on, while the RUN indicator remains off. It is necessary to check the error flag in the manual of the given PLC in order to locate the cause of the problem and to correct the error.