Product Description:

The ELM3148-0000 is an analog measurement terminal from Beckhoff that belongs to the ELM EtherCAT Terminals series. It is installed on an EtherCAT I/O strand to capture differential sensor signals and forward digitized values to the controller. The resulting data can be used for condition monitoring, process regulation, and data logging tasks in industrial automation.

This module offers 24-bit resolution, including the sign bit, across eight differential channels, so even small signal changes are represented with high numerical depth. Each channel is sampled at 1 kSPS per channel, and this fixed rate allows control-loop timing to be aligned without external multiplexers. The hardware provides eight input channels and processes their signals with a delta-sigma converter that operates internally at 8 MSPS. This oversampling technique improves noise performance when measuring low-level analog signals. Ahead of the converter, an analog filter with a cutoff frequency of 2.75 kHz (-3 dB) limits high-frequency content and helps prevent aliasing. Signals enter through 2-, 3-, or 4-wire connections, and the low-frequency path includes a 330 Hz filter that further attenuates out-of-band energy before digital processing.

The E-bus isolation is type-tested at 707 V DC, separating field wiring from the internal backplane, while the backplane draws a typical current of 300 mA. Field contacts can tolerate voltage swings of up to ±30 V, but the recommended operating limit is ±12.5 V to maintain linearity. Channel 8 delivers its first sample with a positive 700 µs offset relative to the other channels, and this delay must be considered during synchronous data acquisition. Typical thermal dissipation is 2 W, so cabinet ventilation must remove the generated heat. Wiring terminates on a 6-pin push-in service plug, and the channels are not isolated from one another. The terminal has IP20 ingress protection and is intended for installation inside a suitable control enclosure.