BECKHOFF EtherCAT Technology Section I - Manual (Page 95)

SII EEPROM
Slave Controller – Technology I-75
11.2.1 SII EEPROM Errors
The ESC retries reading the EEPROM after power-on or reset once if an error has occurred (missing
acknowledge, wrong checksum). If reading the ESC Configuration Area fails twice, the Error Device
Information bit is set, and the PDI Operational bit in the ESC DL Status register (0x0110[0]) remains
clear and the EEPROM_Loaded signal (if available) remains inactive. The process memory is not
accessible until the ESC Configuration Area is loaded successfully.
All registers initialized by the ESC Configuration Area keep their values in case of an error. This is also
true for the Error Device Information bit as well as the PDI Operational bit. Only if the EEPROM was
loaded/reloaded successfully, the registers take over the new values (except for Configured Station
Alias register 0x0012:0x0013 and ESC Configuration register bits 0x0141[1,4,5,6,7]
– enhanced link
detection).
The SII EEPROM interface has these error status bits in register EEPROM Control/Status
(0x0502:0x0503):
Table 40: SII EEPROM Interface Errors
Bit Name Description
11 Checksum Error ESC Configuration Area checksum is wrong (after device
initialization or EEPROM reload). Registers initialized with
EEPROM values keep their value.
Reason:
CRC error
Solution: Check CRC
12 Error Device
Information ESC Configuration not loaded
Reasons: Checksum error, acknowledge error, EEPROM
missing
Solution: Check other error bits
13 Error Acknowledge/
Command Missing Acknowledge or invalid command
Reason:
a) Missing acknowledge from EEPROM chip (see
below). EEPROM chip is busy performing
operations internally or EEPROM chip is not
available.
b) Invalid command issued
Solution: a) Retry access. EEPROM device does not
acknowledge if it is internally busy.
b) Use valid commands
EEPROM Emulation only: Missing Acknowledge error indicates
a temporary failure. Invalid command error is automatically
supported by the EEPROM interface.
14 Error Write Enable Write without Write Enable (ECAT control only):
Reason:
ECAT issued a write command without Write Enable
bit set (0x0502[0])
Solution: Set Write Enable bit in the same frame as the write
command