EL3742 - Introduction
Two-channel analog input terminal, differential inputs, 0 ... 20 mA with oversampling
The EL3742 analog input terminal handles signals in the range from 0 to 20 mA. The voltage is digitized to a resolution of 16 bits, and is transmitted, electrically isolated, to the controller. The input channels of the EtherCAT Terminals have differential inputs and possess a common, internal ground potential.
The signals are sampled with a configurable, integer multiple (oversampling factor: n) of the bus cycle time (n microcycles per EtherCAT bus cycle). The EtherCAT Terminal generates a set of n process data per channel for each EtherCAT bus cycle, which is accumulated and transferred in the next bus cycle. The timebase of the terminal can be synchronized precisely with other EtherCAT devices via distributed clocks. This procedure enables the temporal resolution of the analog input signals to be increased to n times the bus cycle time.
Responses at equidistant intervals are made possible in conjunction with the EL4702/EL4732 (analog output terminal with oversampling) or any other distributed clocks-capable EtherCAT device.
The maximum sampling rate of the EL3742 is 100 ksps (10 µs sampling) at a recommended input signal bandwidth of 0..30 kHz.
Information on the distributed clocks can be found in the separate System description.