The DAQ system is an open-source/open hardware (Creative Commons 4.0) embedded microcontroller system that provides data acquisition and control. The DAQ system provides digital I/O (up to 576 I/O pins), digital relay outputs (solid-state relays or mechanical relays, up to 160 relay outputs), 16-bit analog input (up to 128 single-ended channels or 64 double-ended channels), and 12-bit analog output (up to 32 channels).
The DAQ system can be controlled via Ethernet, USB, or RS-232 serial connections. It supports the use of a Netburner MOD54415 module, a Raspberry Pi (w/40-pin connector) board, or a Teensy 3.2 (Arduino software compatible) board.
When paired with a Netburner MOD54415 evaluation board, the DAQ system provides a full Ethernet-based command structure that can be controlled from a host PC (Windows, MacOS, Linux, or any other system supporting TCP/IP and socket communication).
The DAQ system was designed for use in safety critical systems (nuclear research reactors) and is well documented and tested. The documentation is suitable for V&V for a particular site installation and follows IEEE guidelines for system/software requirement specifications, software design description, test cases, and test procedures.
The DAQ system consists of several separate circuit boards:
- DAQ_IF host computer interface module (provides connectivity and control)
- PPDIO96: digital data I/O. Up to 96 I/O lines per PPDIO96 and up to six PPDIO96 boards may be attached to a single DAQ_IF board (total of 576 digital I/O lines).
- PPOPTO-12: 12-channel opto-isolation board. Up to eight of these may be connected to a single PPDIO96 board providing optical isolation for external signals connecting to the DAQ system.
- PPRelay-12: 12-channel mechanical relay digital output board. Each relay supports NC/COM/NO (normally closed / common / normally open) contacts and can handle 2A@30VDC. Each PPRelay-12 board also provides four digital output lines capable of sinking up to 150mA each. Each relay supports NC/COM/NO (normally closed / common / normally open) contacts and can handle 2A@30VDC. Connects to PPDIO96 to provide relay output or matched relay input circuits. Can also connect with a PPOpto-12 board to provide isolated inputs.
- PPRlyio-12: 12-channel mechanical relay digital I/O board. Typically used to provide inputs to DAQ system with relays mirroring the input values. Each relay supports NC/COM/NO (normally closed / common / normally open) contacts and can handle 2A@30VDC.
- PPSSR-16: 16-channel solid-state relay digital output board. Each relay can handle 1A@30VDC.
- PPAIO-16/4: 16-channel analog input, 4-channel analog output board. Each board supports 16 single-ended 15-bit analog inputs or 8 double-ended 16-bit analog inputs. Each board also provides four 12-bit digital-to-analog circuits and appropriate amplifier circuitry to produce ±5V or ±10V outputs from the DACs. Up to eight PPAIO-16/4 boards may be connected to a single DAQ_IF board (total of 128 single-ended analog inputs/64 double-ended inputs and 32 analog outputs per DAQ_IF).
- PPISO4: 4-channel isolation amplifier board that converts ±10V inputs to ±10V outputs (with adjustable gain and offset settings for each channel). Optional daughter boards provide input and output analog conditioning (e.g., 4-20mA conversion, differential conversion, etc.).
- PPIT: An isolation/trip board supporing single-ended, differential, or 4-20mA inputs which are converted to a voltage and isolated from the input signal. The result is amplified (adjustable gain and offset). The result is fed into an analog trip circuitry than can test for a high value, low value, or a range of values. Out of range values produce a trip condition recorded as a digital output signal and on a FORM-C relay (SPDT or DPDT). The board also supports an isolated analog output as well as test inputs and various other output signals.
- PPAC420: Eight-channel 4-20mA conversion board. Each channel converts a 0-20mA input to a -1.25V to +5V signal (4 mA is 0V) that can be fed to an input channel on a PPAC4 board. Note that one PPAC420 board will drive two PPAC4 boards that will connect to a single PPAIO-16/4 board. Note: this board is deprecated; new designs should probably use the 4-20mA daughterboards on the PPISO4 for 4-20mA input conversion.
- PPBreakout: A 12-channel breakout board that brings out 12 digital I/O lines on the PPDIO96 to a set of screw terminals (typically used as output pins).
- PPBreakin: A 12-channel breakout board that brings out 12 digital input lines on the PPDIO96 to a set of screw terminals; includes 10kΩ pullup resistors on each input pin.