Product Description:

The ELM3504-0000 is a bridge input terminal produced by Beckhoff in the ELM EtherCAT Terminals series. Designed for differential measurement of strain gauges, load cells, or pressure transducers, the unit converts low-level millivolt signals into digital words that an EtherCAT controller can use for closed-loop force, weight, or position monitoring across a machine line. It fits directly onto the DIN rail and uses the E-bus for power and fieldbus communication within compact control cabinets.

Its delta-sigma converter delivers a native 24-bit resolution, which supports micro-newton or gram-level measurement tasks. The oversampling front end captures analog data at 5.12 Msps, then a hardware decimator presents user-visible samples at 10 ksps. With 4 differential channels, each sensor is isolated from the next, so bridge excitation and sensing lines do not interfere. A configurable analog filter attenuates high-frequency noise; the pre-ADC path rolls off at 30 kHz, while a digital post-ADC stage limits bandwidth to 2.6 kHz for flicker-free numerical stability. To protect electronics during wiring, the terminal tolerates contact potentials up to ±36 V when the supply is present. Full- and half-bridge scaling factors of 32 mV/V and 16 mV/V align the module with standard strain gauges, and the 300 µs ramp-up time lets automatic filter engagement track step changes without long settling intervals.

The module draws 720 mA from the E-bus, so the backplane current budget must account for this load. Sensor excitation is sourced internally; up to 21 mA can be delivered per channel, allowing direct supply of most 350 Ω bridges over 2-, 3-, 4-, 5-, or 6-wire topologies through the 6-pin push-in service plug. Thermal losses remain modest at 3 W, keeping cabinet temperatures within typical control-panel limits, while the ±40 V unsupplied contact rating safeguards against misconnections when the controller is off.