HEIDENHAIN PROFIBUS-DP (DPV0) - Manual (Page 27)

Absolute encoder installation
27
3.5 LED indication
In order to determine the status of the encoder two LEDs are
visible from the rear end of the encoder. The module LED
indicates status of the module itself. The bus LED indicates the
status of the bus. The table below defines the diagnostic
messages using a red (BUS) and a bicolor, Red/Green, LED
(MODULE).
Bus status Module Meaning Cause
Off Off No power
Red Green No connection to other
device. Criteria :No data
exchange
- Bus disconnected
- Master not available/
switched off
Red 2) Red 2) No connection to other
device. No connection
between EnDat encoder
and PROFIBUS PCB.
No connection to EnDat
encoder at power up.
Blinking 1) Green Parameterization or
configuration fault
- Configuration received
differs from the supported
configuration.
- Parameter error in the
parameterization.
Green Red System failure - Diagnosis exists, slave in
data exchange mode.
- Position error
Green Green Data exchange. Slave and
operation OK
Table 10 LED indication encoder
1) The blinking frequency is 0.5 Hz. Minimal indication time is 3 sec.
2) Position error is when an alarm occurs in the encoder or if the EnDat encoder is
disconnected from the PROFIBUS interface PCB.