LED in PLC 135u-CPU 928B

Hello Dears,
I have 2 question and hope u would be help me,
1st I want to know the working of the led in CPU 928B card on PLC 135U, and I want to know when LED flash slow or fast what happend and what must we do.
2nd we have 2 PLC 135U-CPU 928B and one of them have too many block (about 250 ) and when we want to stop and start, after overall Reset when we r in stop mode we transfer data to PLC,and after when we want to start,PLC doent go to start and RED flashing LED is appeared.
so now we start plc without any data and the last for executing OBs we reastart and then start only cold restart.
what do u think about this problem? may u help me.
beforehand many thanks from all.
bye

MEHRDAD

Flashing slowly:
The CPU is in the "STOP" mode.
The CPU itself prompte the "STOP" mode (possibly also of the other CPUs).
Typical causes:
ADF,QVZ,LZF,BCF, controller error, interrupt collision, cycle fault, BSTACK overflow, ISTACK overflow, stop command, end of program test.
If you switch the mode selector to "STOP", the flashings stops and the LED is lit continuously.

Flashing quickly:
The CPU is in the "STOP" mode.
An overall reset has been requested. This request can be generated by the CPU itself or also by on operator input.

Try find manual 6ES5998-2UL22 for 928B