EJ2128 - Switching behavior

The output circuit of the EJ2128 EtherCAT plug-in module is optimized for fast signal output. The EJ2128 module has a push/pull output stage that actively switches to 5 V/3.3 V and 0 V for this purpose.

The push stage is overcurrent- and short circuit-protected, the pull stage (switching to 0 V) is not. This may have to be taken into account when inductive loads are switched off.

The length of time required for a signal change as a rising/falling edge from the central control unit (ESC, EtherCAT slave controller) to the connection point at the rear of the module is specified for an EtherCAT plug-in module as T_ON/T_OFF < 1 µs, both for a rising edge (T_ON) and for a falling edge (T_OFF). Due to this short absolute signal cycle time the temperature drift during the cycle time is also very low.

The edge steepness of the output drivers is < 1 µs/5 V or < 1 µs/3.3V.

The EJ module and the actuator should always be supplied from a power supply unit. Furthermore, appropriate potential equalization must be ensured.

Measurement of time delay Although the time delay between the physical real edge at the ESC output and the edge at the connection point at the rear of the module is optimized by the electronics to < 1 µs, it cannot be shorter than a certain minimum time. If the user has a particular need for precision, calibration must be carried out, and the precise time delay measured in accordance with the environmental conditions.