BECKHOFF EtherCAT Technology Section I - Manual (Page 109)

LED Signals (Indicators)
Slave Controller – Technology I-89
15.3 STATE LED and STATE_RUN LED Signal
The STATE LED is a bicolor-LED combining RUN and ERR LED. Since the RUN LED part of the
STATE LED must be turned off while the ERR LED part is active, the RUN and ERR LED signals
cannot be simply combined to drive the bicolor LED. Some ESCs support a STATE_RUN signal,
which is turned off while ERR LED is on, so STATE_RUN and ERR signals can be used to drive the
bicolor STATE LED.
Otherwise the logical combination “RUN and not(ERR)” has to be used to control
the RUN LED part of the STATE LED.
15.4 LINKACT LED
The Link/Activity state of each port is displayed with the LINKACT LED (green).
Table 56: LINKACT LED States
LINKACT LED Description
Off No link
Blinking Link and activity
On Link without activity
It is recommended to use the LINKACT LED signals of the ESCs instead of the Link/Activity LED
signals of the PHY, because the ESC signals reflect the actual link/activity state of the device
– not
only the state of the PHYs –, and the ESC signals adhere to the ETG.1300 EtherCAT Indicator and
Labeling Specification.