BECKHOFF CU8870-0000 - Manual (Page 12)

Installation
CU8870-0000 10
3.5 LED-Diagnosis
LED Mapping Status Meaning
off no power supply connected (see chapter power supply for details) P10 Power supply
lights green Device is operational
off no CF card inserted P20 CF LOCK
lights green CF-card is inserted and electrical connected
off no access on the media P21 ACCESS
flashes Read / write access on the media