Fig. 1 El5021 El Terminal, Standard Ip20 Io Device With Batch Number And Revision Id (Since 2014/01); Fig. 2 Ek1100 Ethercat Coupler, Standard Ip20 Io Device With Batch Number - Beckhoff EK1101 Documentation

Foreword
D - prefix designation
ww - calendar week
yy - year
x - firmware version of the bus PCB
y - hardware version of the bus PCB
z - firmware version of the I/O PCB
u - hardware version of the I/O PCB
Example: D.22081501 calendar week 22 of the year 2008 firmware version of bus PCB: 1 hardware version
of bus PCB: 5 firmware version of I/O PCB: 0 (no firmware necessary for this PCB) hardware version of I/O
PCB: 1
Unique serial number/ID, ID number
In addition, in some series each individual module has its own unique serial number.
See also the further documentation in the area
• IP67: EtherCAT Box
• Safety: TwinSafe
• Terminals with factory calibration certificate and other measuring terminals
Examples of markings
Fig. 1: EL5021 EL terminal, standard IP20 IO device with batch number and revision ID (since 2014/01)
Fig. 2: EK1100 EtherCAT coupler, standard IP20 IO device with batch number
10 Version: 3.6 EK110x, EK15xx