eXRCPU
Main Processor Layer
Detailed description
The eDAQXR family is the next generation in the HBM eDAQ product line of rugged, mobile data acquisition modules. The EBRG bridge layer provides significant improvements in data throughput, supports seamless networking and a state of the art web-based interface. The layer allows flexible configurations for a variety of applications.
In this eDAQXR bridge layer, each of the 16 connectors has both 120-Ohm and 350-Ohm completion resistors connected to a different pin. Formerly, four (4) different eDAQ bridge layers supported the 120-Ohm or 350-Ohm completion resistors and analog output.
The EBRG layer offers 16 simultaneously sampled low-level differential analog inputs through independent connectors. An extremely versatile layer; the layer works with both amplified and unamplified transducers including: strain gauges, accelerometers, pressure transducers, load cells, and other general analog signals. The EBRG provides excellent strain gage conditioning with support for quarter-, half- and full-bridge configurations. Automatic balancing and gain settings as well as software selectable sample rates, excitation, and digital filtering; simplify the set-up of a strain channel. There are several calibration options including defined value, external and multipoint calibrations as well as shunt calibrations with embedded software tools. The EBRG also provides four shunt calibration resistors per channel with software selectable shunt direction for either upscale (-Sig to -Ex) or downscale (-Sig to +Ex) calibrations.
This layer includes an analog output function. Outputs are filtered analog output signals that can be used in the creation of time-domain lab durability tests. When setting up the laboratory simulation, bring the eDAQXR system into the lab with the component or vehicle. This practice is highly recommended, as it ensures that all of the transducer instrumentation and properties are identical for the lab simulation as they were for the field data collection. Instead of being recorded, the analog out signals are sent as time series data for the test rig to analyze. The controller can then develop drive files that are played into the test rig reproducing exact field dynamics in the lab. Each output channel is associated with the corresponding (like-numbered) input channel on the EBRG board. Calibration files, directly compatible with popular simulation software, that scale the analog outputs to engineering units are provided. The maximum analog output voltage is ±10 volts. Each of the 16 analog channels contain a three-pole Butterworth filter which attenuates frequencies above 25 KHz. These filters smooth out the stair-steps created by the channel’s digital to analog converter.
Ordering Options
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1-EXR-EBRG-2 | eDAQXR Bridge Layer Includes: Six (6) M3 8mm screws and sixteen (16) 2 m transducer cable (1-SAC-TRAN-MP-2-2) |
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1-SAC-TRAN-MP-2-2 | Transducer Cable - Male/Pigtail - 2 Meters Length | ||
1-SAC-TRAN-MP-10-2 | Transducer Cable - Male/Pigtail - 10 Meters Length | ||
1-SAC-TRAN-AO-2-2 | Transducer Cable - Analog Out - 2 Meters Length | ||
1-EBB-AO-2 | Breakout box - Analog Output eDAQ EHLS Layers | ||
1-SAC-EXT-MF-0.4-2 | Extension Cable - Male/Female Connectors - 0.4 Meters Length | ||
1-SAC-EXT-MF-2-2 | Extension Cable - Male/Female Connectors - 2 Meters Length | ||
1-SAC-EXT-MF-5-2 | Extension Cable - Male/Female Connectors - 5 Meters Length | ||
1-SAC-EXT-MF-10-2 | Extension Cable - Male/Female Connectors - 10 Meters Length | ||
1-SAC-EXT-MF-15-2 |
Extension Cable - Male/Female Connectors - 15 Meters Length |
Specifications
Parameter | Units | Value |
---|---|---|
Storage temperature range | °C [°F] | -40 ... +85 [-40 ... +185] |
Operating temperature range Altitude de-rating maximum temperature a 0 m maximum temperature a 2500 m maximum temperature a 5000 m |
°C [°F] - °C [°F] °C [°F] °C [°F] |
-40 ... +80 [-40 ... +176] - +80 [+176] +70 [+158] +55 [+131] |
Relative humidity range | % | 5 ... 100 |
Protection class | - | III |
Degree of protection | - | IP65/IP67 per EN 60529:2005 (When the eXRCPU is attached to eDAQ-Plus layers (EBRG, EHLS, EDIO, EITB, ENTB) the IP rating is downgraded to IP54) |
FCC class for digital devices eXRCPU and eDAQXR layers eXRCPU with eDAQ-Plus layers |
- - - |
- Class B, eXRCPU alone or attached to eDAQXR layers Class A, when the eXRCPU is attached to eDAQ-Plus layers (EBRG, EHLS, EDIO, EITB, ENTB) |
EMC requirements | - | CE conformity test per EN 61326-1:2012 |
Evaluated for safety according to | - | IEC61010-1:2010 |
Mechanical test
Vibration acceleration duration frequency Shock acceleration pulse duration number of impacts |
- - m/s2 min Hz - m/s2 ms - |
- accord. MIL-STD202G, Method 204, Test Condition D 100 450 5 ... 2,000 accord. MIL-STD202G, Method 213B, Test Condition H 750 6 18 |
Load dump | - | ISO 16750-2:2010 Test B 63 Vpeak |
Dimensions (H x W x D) | mm | 68 x 197 x 200 with base and lid |
Weight | g [lb] | 2,004 [4.42] with base and lid |
Bridge excitation voltage voltage initial tolerance (3σ) single 5-V temperature drift (1σ) single 5-V temperature drift (3σ) single 2.5-V temperature drift (1σ) single 2.5-V temperature drift (3σ) ±5-V temperature drift (1σ) ±5-V temperature drift (3σ) ±2.5-V temperature drift (1σ) ±2.5-V temperature drift (3σ) |
- V % ppm ppm ppm ppm ppm ppm ppm ppm |
- ±2.5 or ±5 0.1 5 15 3.3 10 10 30 6.66 20 |
Quarter-bridge completion resistance resistance initial tolerance (1σ) initial tolerance (3σ) temperature drift (1σ) temperature drift (3σ) |
- kΩ % % ppm ppm |
- 120 or 350 ±0.0033 ±0.01 ±0.3 ±0.9 |
Specifications (Continued)
Parameter | Units | Value |
Half-bridge completion resistance internal resistance typical initial tolerance (1σ) maximum intial tolerance temperature drift (1σ) temperature drift (3σ) |
- kΩ % % ppm ppm |
- 12.5 (50-kΩ split) ±0.025 ±0.05 ±0.66 ±2 |
Shunt calibration resistance resistance initial tolerance (1σ) intial tolerance (3σ) temperature drift (1σ) temperature drift (3σ) |
- kΩ % % ppm ppm |
- 49.9, 100, 200 and 499 0.033 0.1 10 30 |
Analog out accuracy | % of full scale | 0.25 |
Analog inputs surviving over voltage | V | ±125 |
Maximum excitation output power per channel | mW | 300 |
Maximum current output | mA | 42 |
Power consumption 1 no load 350-Ω full bridge at ±5 V 350-Ω 1/2 or 1/4 bridge at ±5 V 350-Ω full bridge at ±2.5 V 350-Ω 1/2 or 1/4 bridge at ±2.5 V 120-Ω full bridge at ±2.5 V 120-Ω 1/2 or 1/4 bridge at ±2.5 V |
- W W W W W W W |
- 4.55 11.8 8.6 7.1 5.8 12.1 8.6 |
Typical input offset current over temperature 2 3 | pA/°C | ±8 |
Typical input-referred voltage drift over temperature (1σ) 2 4 5 |
μV/°C |
±0.25+1.5/G1 |
Gain drift over temperature 2 typical (1σ) maximum (3σ) |
- ppm/°C ppm/°C |
- 2.5 10 |
Analog output channel impedance 6 | Ω | 1000 ±50 |
1 Power consumption measurements are taken with the stated load on all 16 channels and include the efficiency of the power supply.
2 Quantities are given per °C temperature change from the temperature at calibration.
3 Use change over temperature to calculate the offset voltage over temperature. Offset voltage [V] = current change over temperature [pA/°C] x change in temperature [Δ°C] x input resistance [10 kΩ].
4 Where G1 is the gain of the first stage. See the gain table in the following section for selected gain settings.
5 The total input referred voltage drift is a combination of drift over temperature at the gain setting [μV/°C] and the drift due to the input current change over temperature (discussed in 3).
6 The 1000-Ohm stabilization resistor in series with the op-amp at the analog output creates an RC filter in addition to the output filter. Typical cable capacitances (Ccable) fall within 18 to 40 picofarads per foot, creating a pole at 1/(2π1000Ccable).
Selected gain settings
Desired Input Range 7 (Vpp) |
Input Stage Gain, G1 |
Second Stage Gain, G2 |
Third Stage Gain, G3 |
Overall Gain |
---|---|---|---|---|
20 |
1 |
1/5 |
1 |
0.2 |
10 |
1 |
2/5 |
1 |
0.4 |
5 |
1 |
4/5 |
1 |
0.8 |
4 |
1 |
1 |
1 |
1 |
2 |
1 |
1 |
2 |
2 |
1.25 |
1 |
4/5 |
4 |
3.2 |
1 |
1 |
1 |
4 |
4 |
0.8 |
1 |
1 |
5 |
5 |
0.625 |
1 |
4/5 |
8 |
6.4 |
0.5 |
1 |
1 |
8 |
8 |
0.4 |
10 |
1 |
1 |
10 |
0.25 |
1 |
1 |
16 |
16 |
0.2 |
10 |
1 |
2 |
20 |
0.125 |
1 |
1 |
32 |
32 |
0.1 |
10 |
1 |
4 |
40 |
0.08 |
10 |
1 |
5 |
50 |
0.0625 |
10 |
4/5 |
8 |
64 |
0.05 |
10 |
1 |
8 |
80 |
0.04 |
100 |
1 |
1 |
100 |
0.025 |
10 |
1 |
16 |
160 |
0.02 |
100 |
1 |
2 |
200 |
0.0125 |
10 |
1 |
32 |
320 |
0.01 |
100 |
1 |
4 |
400 |
0.008 |
100 |
1 |
5 |
500 |
0.00625 |
100 |
4/5 |
8 |
640 |
0.005 |
100 |
1 |
8 |
800 |
0.004 |
100 |
1 |
10 |
1000 |
0.0025 |
100 |
1 |
16 |
1600 |
0.00125 |
100 |
1 |
32 |
3200 |
7 The maximum A/D converter input, which is the product of the input stage and the overall gain, is 4.096 Vpp.
Note: This table is a representative list only and does not show all available gain settings. To check the gain settings for a defined channel, see the Test configuration Channel settings in the eDAQXR web interface. “Gain 1” is the input stage gain, “Atten2” is the second stage gain and “Gain2” is the third stage gain.
Channel Noise Characteristics
The input-referred noise and the signal to noise ratio (SNR) are defined by the following two equations:
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where GO is the overall gain setting and N is the noise at the input of the A/D converter, defined by one of the following three
equations depending on the gain of the first stage (G1):
and where xn is the cutoff frequency of the digital or analog filter to a specified maximum.
xn | Maximum Value | Cause |
---|---|---|
x1 | 24 kHz | analog filter cutoff |
x2 | 13 kHz | secondary filter cutoff |
x3 | 15.7 kHz | early rolloff of first stage when G1 = 100 |
Note that when selecting the sampling rate in the web interface, the cutoff frequency of the selected filter is one third of the sampling rate.