DAQ System Recommendation

[jsculley]

I have a project for which I need to do some data acquisition and I have no idea where to begin in terms of DAQ hardware selection, so I'm looking for some help.  I'd like to keep the cost as low as possible.

The measurement hardware consists of 12 thermocouples, and 12 bi-axial strain gauges. I'll be collecting data for a few days, but the sample speed does not need to be fast at all.  Measurements every 30 minutes would be acceptable, but faster is OK as well. 

Assuming I have the thermocouples and strain gauges and nothing else, what do I need to gather the data from the hardware and display meaningful data on a screen with as little setup, configuration and programming as possible?

From a quick session with the CompactRIO configurator, I have come up with this:

NI 9210  -- 4-Channel, 14 S/s Aggregate, ±80 mV C Series Temperature Input Module -- Qty 3 ($439 ea)

NI 9219  -- 4 Ch-Ch Isolated, 24-bit, ±60V,100S/s Universal AI Module -- Qty 3 ($1473 ea)

cRIO-9066 -- 8-slot Chassis with Integrated 667 MHz Dual-Core Cntlr -- Qty 1 ($2572)

NI 9901 -- Desktop Mounting Kit -- Qty 1 ($70)
NI 9915 -- DIN Rail Mount Kit for 8-slot cRIO-910x/911x/906x/907x and cDAQ-917x/918x -- Qty  1 ($ 42)
NI PS-15 -- Power Supply, 24 VDC, 5 A, 100-120/200-240 VAC Input -- Qty 1 ($292)

FlexLogger -- FlexLogger, Perpetual License, With Media, Include 1 Year SSP -- Qty 1 ($1,731)

Does this look like I've captured the minimum required hardware?  Did I miss anything?  Do I have too much?  Is there a lower cost option I haven't seen?

I also have a question about the strain gauge measurements.  Since I'm using bi-axial strain gauges, would I wire them up in a half-bridge configuration?  If so, can I read data from both gauges?  Or, would I have I wire each gauge up as quarter bridge to read individually?  If they are wired up in quarter bridge configuration, I would need three more NI 9219 for a total of 24 channels, correct?

Thanks for any assistance.

[crossrulz]

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@jsculley wrote:

From a quick session with the CompactRIO configurator, I have come up with this:

NI 9210  -- 4-Channel, 14 S/s Aggregate, ±80 mV C Series Temperature Input Module -- Qty 3 ($439 ea)

NI 9219  -- 4 Ch-Ch Isolated, 24-bit, ±60V,100S/s Universal AI Module -- Qty 3 ($1473 ea)

cRIO-9066 -- 8-slot Chassis with Integrated 667 MHz Dual-Core Cntlr -- Qty 1 ($2572)

NI 9901 -- Desktop Mounting Kit -- Qty 1 ($70)
NI 9915 -- DIN Rail Mount Kit for 8-slot cRIO-910x/911x/906x/907x and cDAQ-917x/918x -- Qty  1 ($ 42)
NI PS-15 -- Power Supply, 24 VDC, 5 A, 100-120/200-240 VAC Input -- Qty 1 ($292)

FlexLogger -- FlexLogger, Perpetual License, With Media, Include 1 Year SSP -- Qty 1 ($1,731)

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1. You are just logging data.  2. You want to avoid programming.  Based on these, you will want to avoid the cRIO line.  Instead, look at a cDAQ.  Assuming you want Ethernet connection and 8 slots, I would go with the cDAQ-9189 ($2k).  I think the modules you selected will still work.

Do you want the desktop mounting or the DIN rail mounting?  There is no point in doing both.

As far as software, I have not used FlexLogger at all.  It looks interesting.  But I have had success with just using DAQExpress, which is free.  DAQExpress has very little display capabilities (just shows a graph for the data), so if you want a good GUI FlexLogger is probably the way to go.

[JensG69]

If you are really looking for a stand-alone system runnning on a compact-RIO, use a cRIO-9056. The 9066 is nearing the end of its life-cycle.

Regards, Jens

[Hansel]

There are also specific C-Series Strain Modules available.  Check out the NI-9235, NI-9236, and NI-9237 modules to see if they fit your strain sensor preference.  These modules should work with cDAQ and cRIO.

[Henrik_Volkers]

Sorry, I'm a  LabVIEW and PXI addicted, however for this usecase I also would look for dataloggers like Keithley/Keysight/Fluke/Yokogawa with multiplexer (in this case relay based?) .   

TCs could be done by all of them, strain bridges are easy if an external power soucre is provided and full bridges are used.

Most of these loggers come with a simple logging software, since no programming should be involved.

Or maybe some of these?

https://www.meilhaus.de/en/dydaqlog.htm

(can't say much about them, just the first thing I found 😉 , but seems to fit the bill)

You didn't mentioned your target uncertainty, or whether a traceable calibration is needed..

Strain gauges: Bi-axis mean you measure strain (force) in two axis? of the shelf sensor? datasheet?

that would mean you need 24 channels (one for each axis of your 12 sensors) or you combine your 24 strain resistors to 6 fullbridges (six axis, 3 force,3 torque??) which end up in 6 channels to read?