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HUGnetLab Overview
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- Category: General Stuff
- Published on Monday, 08 October 2012 18:34
- Written by Ryan Hunt
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HUGnet Lab data acquisition system
Real Time Data | Overview of Celani Replication Experiment
Overview
HUGnet Lab was born out of the need to have high quality data acquisition for virtually any type of analog sensor found in a LENR lab.
Pressure sensors
Strain gauges, load cells
RTD temperature sensors
Thermistors
Thermocouples
Voltage
Current
Watts
Resistance
Joules, Watt hours
At Hunt Utilities Group (HUG) we designed it to make our own laboratory more efficient, but... If you want very flexible distributed data acquisition with high sensitivity, high resolution, low noise,at modest speeds (typically 0.25 second time constants), then HUGnet Lab might be a good choice for you.
The concept of HUGnet Lab is to put the analog to digital converters very close to the analog sensors. This dramatically shortens the length of analog wiring, reducing the associated noise. Those many analog wires get replaced with one thin network wire.
The concept is realized with Small, intelligent, galvanically isolated input modules. All power and communications are on a simple 4 wire bus. An arbitrary number of modules can be paralleled on the same bus.
The bus connects to a laptop computer via the USB port.
Every module is galvanically isolated to reduce pesky ground loops and noise.
Small modules allow more isolation, flexible number of inputs, and more spatial distribution which in turn allows shorter analog wires and lower noise.
The input modules
The input modules are small circuit boards using tiny (0.1 inch on center) terminal strips for connections. Don’t let the small size fool you. Each board Packs two low noise 24 bit analog to digital converters, an ARM microprocessor, power and data isolation, and an RS485 data bus interface with heavy transient protection.
The boards can be mounted in their own heavy aluminum case mounted on a DIN rail, or in snap tracks inside a project, or in a standard american outlet box.
Each module has 8 analog input pins that read both positive and negative voltages. They can be programmed individually as single ended or differential pairs. Each module also has one analog output that can be used for jobs such as controlling a power supply.
Power connections are simple, neat and reliable because the modules are powered from the data bus.
The data bus
The bus consists of 4 wires. Any telephone or cat 5 style wires will work. Two of the wires carry data. The other two provide 9 volts DC to power the modules.
Data is transferred between the module and the host computer on a two wire RS485 bus. Data is at a moderate speed of 115 Kbits per second. This is fast enough to get the job done and slow enough to use slew limited waveforms that are much more robust and less sensitive to cable routing issues.
The bus is well protected against damage from static surges and any combination of connecting the wires wrong. Bus wires are connected to a terminal strip on board.
We find it very convenient to connect modular telephone cords and use 5 way phone jack splitters.
The bus connects to the host computer via a RS485 to USB adaptor.
Software
The software usually runs in a local laptop computer running Linux. The program runs in the background, leaving the computer free to run other programs, such as browsers and graphing.
All the human interface is done via a browser. It makes virtually no difference if the operator is at the local computer or any other computer to which it is networked.
The input modules have firmware in them that tells them how to make the analog to digital conversions, how to filter them, and how to communicate the results. That firmware is automatically downloaded into the module when the operator changes the setup from the browser.