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; Fig. 3 Cu2016 Switch With Batch Number - Beckhoff EL3692 Documentation

Foreword
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
Fig. 3: CU2016 switch with batch number
EL3692 Version: 2.1 9