Programmable Sensor Signal Conditioning Circuit Board

                                                                                  TECHNICAL REQUIREMENTS

                                                            Programmable Sensor Signal Conditioning Circuit Boards

GENERAL: Aberdeen Test Center (ATC) is requesting the design and fabrication of three (3) programmable sensor signal conditioning circuit boards that interface directly to the ATC developed Advanced Distributed Modular Acquisition System (ADMAS) data recorder main processor circuit board. The programmable sensor signal conditioning circuit boards shall physically and electrically interface with the ADMAS hardware. The programmable sensor signal conditioning circuit boards shall provide electrical power to and accept electrical signals from analog sensors such as accelerometers, pressure sensors and strain gages. The circuit board is required to permit the ADMAS recorder record data from analog sensors.  The circuit board shall be designed and fabricated to the meet or exceed the following specifications.

Technical Requirements – 8 channel board.

1. Physical Requirements:

The programmable sensor signal conditioning circuit boards must fit inside the ADMAS chassis and attach to the ADMAS main processing circuit board.  The ADMAS main board has space to accommodate two (2) independent Programmable Sensor Signal Conditioning Boards. The circuit board must maintain the following requirements.

1. Maximum size 3.55” (90.17 mm) wide by 2.755” (69.977 mm)  deep by 0.394” (10 mm) high.
2. Location of physical attachments to match drawing Peripheral Base.pdf (Attachment 1)
3. Physical location of interface connectors designated by drawing Peripheral Base.pdf (Attachment 1)

1. Environmental Requirements:

The programmable sensor signal conditioning circuit boards will reside in an ADMAS chassis that is subject to variable environmental conditions because the ADMAS is utilized in moving military vehicles experiencing all possible terrain and environmental environments. Therefore the circuit board must meet the following environmental requirements.

1. Operating temperature range of -40 Deg. F to 178 Deg. F.
2. Operating Relative Humidity of 10% to 90 %
3. Vibration requirement 0.015 g^2/Hz 5-500 Hz
4. Shock requirement 20 g 11ms half-sine

1. Electrical Requirements:

The programmable sensor signal conditioning circuit boards must interface to the ADMAS main processing circuit board through a 40-pin 2-row header connection(s). The circuit board must maintain the following requirements.

1. Maximum power draw of 500 mA at 5 VDC
2. Power connection through PCIE connector
3. Digital data interface through a Samtec QFS-026-04.25-L-D-A connector
4. Interface to analog input through a 40-pin 2-row header connection
5. Pass through auxiliary excitation voltage of 5 VDC (fused at 500 ma)
6. Pass through auxiliary excitation voltage of 12 VDC (fused at 500 ma)

1. Circuit Requirements:

The programmable sensor signal conditioning circuit boards must perform the following functions and have the following capabilities. The circuit board will accept analog signals from sensors. The programmable features of the circuit will set low pass filtering, gain and digitization rates for each input. The digitized signal will then be transferred to the ADMAS main processor board through an RS-422 interface at a rate of 12 Mbps.

1. 1. Accept a maximum of eight (8) analog sensor inputs (channels).
      1. Minimum sigma delta 24-bit A-to-D conversion with anti-aliasing filter per channel.
      2. Direct measurement of electrical signals range of -10 to 32 VDC.
      3. Excitation bridge excitation of 2.048 volts DC
      4. Auxiliary excitation source of 5 VDC and 12 VDC at 100 mA.
      5. Internal 100 KΩ shunt resistors for bridge circuit calibration
      6. Programmable gain up to from 1/16 to 512
      7. 8 pole programmable Butterworth filter for sample rates up to 1200 samples-per-second.
      8. 10 pole Linear Phase tracking low-pass filter with value determined by sampling rate selected
      9. Programmable sample rate with lowest required maximum sampling rate of 10,000 samples-per-second-per-input, simultaneous sampling of 8   channels.
      10. Able to accept a 20 MHz sampling clock signal from host (ADMAS)
      11. Software controlled Wheatstone bridge circuit balancing

1. Software Requirements:

The programmable sensor signal conditioning circuit board operational settings must be programmed by the ADMAS. To accomplish this the board must interface with the ADMAS using Titan Recorder protocol over RS-422.

Calibration: All data acquisition modules shall have a calibration certificate certified per MIL-STD-45662A and ANSI/NCSl Z540-1-1994 and valid for one (1) year from the data of delivery.

Warranty: For production units, a manufactures warranty covering all hardware and software for a minimum of one (1) year from date of delivery shall be included.