How can we slove this problem?Safety processor X20SL8000 has LED red light on letter “F”, “I” and “L” which are brightly than letter “A”
Here you have link to documentation B&R Online Help, so from LEDS you can identify state of safety controller.
You may need more information than only the state of the LEDs.
I’d expect some useful information in the logger.
See also this post which might be helpful: Troubleshooting Steps for Connecting to SL or SLX Safety Controllers