BECKHOFF EL1904 - Manual (Page 14)

Product description
12 EL1904
3 Product description
3.1 General description
EL1904 - TwinSAFE digital four channel input terminal
The EL1904 is a digital input terminal for encoder with floating contacts for 24 V
DC
. The Bus Terminal has
4 fail-safe inputs.
With two-channel connection, the EL1904 meets the requirements of IEC 61508:2010 SIL 3, DIN EN ISO
13849-1:2006 (Cat 4, PL e), NRTL, UL508, UL1998 and UL991.
The TwinSAFE terminal has the typical design of an EtherCAT terminal.