The small form-factor boards were developed to support small and light instruments systems that may be attached to autonomous gliders and floats and other vehicles that are small and buoyancy sensitive. In addition, deep instruments require thick walls. For a given maximum depth, the wall thickness is nearly proportional to the outside diameter of the pressure case. Thus, narrow boards allow for a considerable reduction in weight and volume of deep instruments.
Our line of small form-factor boards provide a complete instruments system and consists of:
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The µASTP which is the analog signal conditioning board that services 2 shear probes, 2 FP07 thermistors, 3 accelerometers and a pressure transducer.
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The Filter-ADC board which provides anti-aliasing low-pass filtering for all micro-structure signals and the accelerometers (for a maximum of 15 channels), and has a low-noise extremely linear Analog-to-Digital Converter.
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The RSTRANS which is used to communicate with the ship-based data acquisition system over a tether. In addition, the RSTRANS provides 2 channels of frequency counting to support a Sea-Bird SBE3 thermometer and a SBE4 conductivity sensor. This board is used for real-time data acquisition over a 4-conductor link. Two conductors are used for bi-directional communication and the other pair is used for power.
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A Persistor CF2 Interface board. This supports the CF2 data acquisition system, provides the logical interface to the ADC output of the Filter-ADC board, controls the power-up and power-down process, and also provides 2 channels of frequency counting for the SBE3/4. The CF2 interface is used with all autonomous self-recording instruments. It has enough data storage to record 150 km of profiling if the sampling rate is properly matched to the speed of the profiler, such as an ARGOS float, for example.
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The Power-2 power supply board was designed to work “smartly” with the new Persistor based internally recording instrument system. It can be turned on with a remote command and will power down gracefully in full co-operation with the Persistor-based data recorder. The Power-2 board can also be configured to automatically turn on and off when external power is supplied or removed.
The fully isolated DC-DC converter modes on the Power-2 board provide ±5V DC for analog boards, 3.3V DC for digital boards, 12V DC for a Sea-Bird thermometer and conductivity sensor, ±15V DC for other devices and raw input power for devices such as pumps that do not need isolated and regulated power.
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The compass – EM current meter board carries a 3-axis magnetometer that can be used as a compass. In addition, it supports a completely isolated measurement of the battery voltage in an instrument system, and the 2-component signals from a geo-electro-magnetic current meter of the Sanford style.
All outputs are digital and connect to the serial instrument bus (SIB), which is used on all small form-factor instruments.
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ODAS5-IR is the data acquisition program used in all internally-recording instruments with a Persistor data acquisition system. The setup file and data file format are identical to those produced by ODAS4-RT and ODAS4-IR which are used, respectively, with real-time telemetering instruments (off all form-factor sizes) and with large form-factor internally recording instruments that use a PC/104 recording system.
All data processing software developed for ODAS4 is compatible with data collected with ODAS5.
All small form-factor boards are 1.75 inches wide, except for the CF2 interface board, which is 2 inches wide(the width of the CF2 processor board). Lengths vary and can be found in the detailed specification for each board.
In order to achieve the narrow width of the small form-factor boards, these boards use a bi-directional serial instrument bus to communicate the requests for data and the data response from the boards. The conventional boards of 3 inch width use a bi-directional parallel bus.
The reduction in board size has been achieved without any compromise in performance.