BECKHOFF EtherCAT Technology Section I - Manual (Page 108)

LED Signals (Indicators)
I-88 Slave Controller – Technology
15.2 ERR LED
The ERR LED indicates local errors and application errors. It is either connected to the application
controller or to the ESC (optional ESC feature). If it is connected to the ESC, some errors are
automatically indicated by the ESC, other error states are detected by the application controller and
indicated by writing to the ERR LED Override register 0x0139.
The following ERR LED states can be automatically generated by an ESC, without interaction of an
application controller. The support of individual error states is ESC specific.
Table 54: Automatic ESC ERR LED state indication
ERR LED Description Examples
Off No error
Flickering (fast) SII EEPROM loading error no SII EEPROM device, SII CRC error
Blinking (slow) Invalid hardware configuration ESC pin sharing violation
Single Flash AL Status register Error
Indication bit 0x0130[4] is set
while device emulation is
disabled Local application controller sets Error
Indication bit.
NOTE: E.g., if the µController makes a state change
with Error Indication bit 0x0130[4] set after a
Process Data Watchdog Timeout, it has to manually
set the ERR LED to Double Flash again (otherwise
the ESC would generate a Single Flash due to the
Error Indication bit automatically).
Double Flash Process Data Watchdog
timeout (edge detected) while
device is OPERATIONAL master is disconnected/not sending process
data any more
On PDI Watchdog timeout (edge
detected) or Build-In self-test
error local application controller failure or self-test
failure
NOTE: Do not confuse the application ERR LED with the port receive error LEDs (PERR(x)) supported by some
ESCs.
15.2.1 ERR LED override
If the ESC supports the ERR LED, the local application (and the master) is able to control the
ERR LED via the ERR LED override register.
The ERR LED override is disabled automatically if an error is detected by the ESC which is associated
with an ERR LED blink code.
Table 55: Registers for ERR LED control
Register Address Name Description
0x0139 ERR LED Override
Direct control of the ERR LED from ECAT
and/or PDI