BECKHOFF EL7037 - Manual (Page 46)

Installation
4.4 Mounting of Passive Terminals
Note
Hint for mounting passive terminals
EtherCAT Bus Terminals (ELxxxx / ESxxxx), which do not take an active part in data trans-
fer within the bus terminal block are so called Passive Terminals. The Passive Terminals
have no current consumption out of the E-Bus To ensure an optimal data transfer, you
must not directly string together more than 2 Passive Terminals!
Examples for mounting passive terminals (highlighted)
Fig. 31: Correct configuration
Fig. 32: Incorrect configuration
EL70x7 46 Version 1.0