EBRG/ELBRG bridge layers

The EBRG/ELBRG High Level Simultaneously Sampled (High Level SS) layer is a high performance layer that supports multiple adapter modules to extend the range of supported transducers. The layer supports powered inputs with configurable full scale ranges from +/-64 mV up to +/-74.9 V.

The EBRG supports 16 input signals. The ELBRG supports 4 input signals.

The boards condition each of the input signals by means of programmable excitation circuitry, an eight (8) pole Butterworth analog guard filter, programmable amplifier gain and offset, 16-bit analog to digital converter sampling at 100000 S/s in the Decimal sample rate domain (or 98304 S/s in the Binary domain). The EBRG/ELBRG features simultaneous sampling for all channels, programmable digital filters, and the output sample rate achieved by means of multiple stages of combined down sampling / digital filtering.

Some other features are itemized as follows.

  1. Differential inputs provided for the analog input signals.
  2. The EBRG has synchronous sampling with other EHLS, EBRG and EDIO layers. The ELBRG has synchronous sampling with other ELHLS, ELBRG and ELDIO layers.
  3. Completely flexible configuration of filter type, filter pass bandwidth, and sample rate on a per channel basis.
  4. For EBRG layer models 02 and above, an optional analog output sub board is available to provide high level analog output signals for each channel.
  5. For EBRG layer models 02 and above, the excitation is provided on 4 channel Bank basis (i.e., the excitation voltage for Bank 1 [channels 1-4] can be selected independent of the excitation voltages selected for the other three (3) Banks).

Connect transducers to the EBRG/ELBRG individually using the M8 connectors located on the front panel.

Each independent channel contains programmable transducer power, an eight-pole Butterworth analog guard filter, a 16-bit A/D converter, software selectable digital filtering and output sample rate options of up to 100 kHz.

The EBRG/ELBRG layer supports full- and half-bridge types with a resistance from 100 to 10000 ohms and quarter-bridges with a resistance of either 120 or 350 ohms. All bridge configurations are accomplished using programmable switches (i.e., there are no jumpers), however, the quarter-bridge choice of 120- or 350-Ohm completion resistor is a factory installed option. A set of internal shunt resistors with selectable shunt direction is available for calibration purposes.

The diagram shows the M8 connectors on the EBRG layer.

The diagram shows the M8 connectors on the ELBRG layer.

Wiring diagrams

Analog input

Use the Somat SAC-TRAN-MP Transducer Cable (1-SAC-TRAN-MP-2-2 or 1-SAC-TRAN-MP-10-2) to wire EBRG/ELBRG analog inputs.

NOTE
Do not use this wiring diagram for EHLS/ELHLS channels.

Strain gages

Piezoresistive transducers

Analog Output

The EBRG is available with an optional analog output function to provide high level analog output signal for each channel. Outputs are filtered analog output signals that can be used in the creation of time-domain lab durability tests. Each output channel is associated with the corresponding (like-numbered) input channel on the EBRG board. Connect the analog outputs to the EBRG through the Analog Output connector on the back panel shown in the diagram below.

This diagram shows the analog out connector on the back panel of an EBRG layer.

The outputs are generated from a D/A converter implemented as a unity gain follower to the A/D converter. The eDAQXR/eDAQXR-lite uses the non-inverting unity gain follower by default. Select the Analog output inversion option in the test setup configuration to use the inverting unity gain follower when the channel calibration slope is negative.

NOTE
The EBRG uses a nominal ±2-volt A/D converter. However, do not assume that the user-defined full-scale values are even approximately equivalent to ±2 volts for any particular channel. This is primarily because the eDAQXR automatically provides a minimum over range protection of 1% and the eDAQXR can set gains only at certain discrete values resulting in actual over range protection that is sometimes significantly larger than 1%.