I need an advice (a solution) for my DAQ system (a recommandation to buy)

[dsasorin]

HI.

I'M Sorin from Romania.

I have to found a solution for my system. I need to buy a DAQ  device with ethernet port (output) and Analog Inputs (minimum 12). It would be better if the ports are BNC type (but it is not necessary) . (I need sheelded signals for inputs)

I need ethernet to output because, the PC is far as 40m from Generator (an Electrical power plant), and analog signal is not recommanded in this case, i think. It's a long way (40m) and there is a lot of fields which will disturb my analog signal. So I prefer digital signal to PC (ethernet).

12 short wires to DAQ, and from here 40 m ethernet cable.

So my question is: Is there any DAQ device with those specifications minimum ?  16 analog inputs and Ethernet output ?

I need to work in Labview 8 with it. So I don't want something to programm. I like the Labview interface. I have experience in USB DAQ with analog inputs, so i'd like to continue in this way.

What can you recomand to buy ?

PS: at least 500 Ks/s for all channels (16 analog inputs channels)

Thank you.

[Wayne.C]

Sorin,

Based on the conditions under which you will be operating, I suggest you look at the Compact Field Point product.  It is very easy to access via ethernet and is designed for industrial environments.

[dsasorin]

Hi. I looked for what you said.

First: I am dissapointed that there's not a DAQ device with ethernet output, just USB.

Second: I found a system (compact Field Point), with following components, but I need some

advices, and I have some questions:

  a. NI cFP-2120     (Controller with Ethernet ,128/128 MB)
  b. NI cFP-AI-110   (8-Channel Analog Voltage and Current Input Module for cFP)
  c. NI cFP-BP-4     (4-Slot Backplane for Compact FieldPoint)
  d. NI PS-5             (Power Supply 24VDC, 5A)

1. Do you think I need something else (hardware) for the system to work ?
2. What it will be the maximum speed of data logging ? (Supposing the cFP controller is

working alone in the system)
    For my system with DAQ, it would be nice a 30 KS/s/ch. I want to compare the 2 solutions

(DAQ vs cFP speed)
3. Is the speed of the CPU (from the cFP) responsable for the speed of data aquisition ?
Maybe i choose a cFP controller from 20xx series which is cheaper, i think nowadays.
4. How can I see if the apllication that i build on PC, works also in the cFP ? (I'm mean

the amount of memory and the speed of data aquisition). The PC has 1GB vs. 128MB memory RAM,

3 GHz vs. 188 MHz CPU frequency, 40 MB/s vs. 4 MB/s (i think) HDD write speed.
Maybe the aplication is OK for the PC, but too complex for cFP controller. How can i figure

if it will work ?
5. Is it enough working  with Labview 8 for the aplication ? (from Electrical Power Plant)

Or you think i need Labview Real-Time Software or Labview datalogging and Supervisory

control module ?

PS: I have to know the answers at my questions, BEFORE  i buy those devices.

Thank you for concerning.

[Wayne.C]

What kind of measurements are you going to be making?  This will determine which hardware you have to have.

1 - cFP Hardware.  Fastest cFP analog input is the AI-118 which has a 10kS/s rating.  Suggest the cFP-AI-118 instead of the AI-110.  Depending on what you are measuring, you may be able to substitute a cFP-1804 network interface for the 2120 controller and the BP-4.  This gives you remote I/O that is ethernet based without the cost of the 2120.  If you really need the 30kS/s, then I suggest that you consider the CompactRIO.  Much faster speeds and ethernet based.

2 - DAQmx hardware will always be faster that cFP.  cFP was never designed to do very fast acquisitions. 

3 - Acquisition speed of cFP is determined by the update rate of the I/O modules.

4 - I have seen some very complex applications implemented on a cFP.

5 - If you choose a Real Time target such as cFP or CompactRIO, you will need the Real Time software as well.

Bottom line.  If your application requires the 30kS/s, then cFP is not an option and you would need to consider something like the RIO.

[Jennifer_R]

Hi Sorin,

You may find the tutorial Selecting Your LabVIEW Real-Time Deployment Platform useful.  There are also some interesting links in this thread. 

If you decide to use CompactRIO, you will need LabVIEW FPGA in addition to the LabVIEW Real-Time Module centerbolt mentioned.  The NI 9201 or NI 9205 look like they could work for your system.  More information on modules, chassis, and controllers can be found in the CompactRIO Product Selection Guide. 

[dsasorin]

Hi again.

I want to make you understand what am i doing exactly, to give me the proper answers.
I want to aquire data from 2 places (2 low voltage sources, +/- 10 V, with 6 channels each).
I want the data to be transmitted throught internet, so i decided that i need a controller like cFP 2100, which has web HTTP, file server and Remote Panel.

I conceived a system with the following components:

cFP-BP-4 + cFP-2100 + AI-118
cFP-1804 + AI-118

also 2x cFP-CB-1 , 2x Backplanes and 2x PS-5 and 1 ethernet switch for the two subsystems.

I have a diagram too, for download. Maybe you found some mistakes...

(First, at the power plant, i deploy the application to cFP-2100 Controller from PC, and second, i unplug the PC leaving the controller to do the job, through the ethernet switch. And then, at institute, i see the data with an internet browser.)

I have some questions:

1. If I want to make the aquisition system (5 Ks/s/ch with AI-118), is it really necessary the software Labview Real Time ? We have Labview 8.2 with licence. Why can't I make the application.vi in Labview, (like a DAQ apllication) and then load on cFP 2100 controller ?

2. Is the 2100 controller with AI-118 capable to work with Labview and aquire at 5ks/s ? (the application is not complex, but I don't know if the data can be written in those 64 MB storage at 5KS/S/ch). I will put some conditions, i think, for the data, to record just the data within certain limits. I read somewhere in 2100 controller datasheet, that it can be easily done.

3. I want to use the integrated remote panel to view certain values and to download the files recorded on those 64MB storage, through internet ; and then empty the memory storage. It can be done just with Labview 8.2 all these ?

[dsasorin]

Sorry, here is my diagram.

[Kevin_H]

Hi Soran,

Thank you for contacting National Instruments.  Looking at your project specifications, Compact FieldPoint may not be your best solution.  The AI-118 can measure eight analog inputs at 16-bit resolution at a 10 kS/s sampling rate with multiple voltage ranges.  That sampling rate however, is for all channels combined, meaning you can really only get about 1.25 kS/s if you are using all the channels at once.  You could simply use only two channels on the module, and acquire those channels at 5 kS/s, but in order to achieve that speed, you would need to disable the filter on the module.  This would also mean you would need to purchase multiple AI-118's in order to get your channel count up to 12.

For those sample rates, it might be better for you to consider using Compact Rio or a PXI controller.  Those solutions are also ethernet based, and can provide remote front panel capability as well.

In addition to LabVIEW 8.2, you are going to need the LabVIEW Real-Time 8.2 module in order to transfer code to these targets. 

Let me know if I can offer any more help!

Kevin H

[dsasorin]

I read something else about AI-118.....

Down here, I uploaded a screenshot from pdf file specification.

Maybe i didn't understood....

[Kevin_H]

Hi Sorin,

You are understanding that document correctly.  The AI-118 module itself can take samples at 10k/s per channel, and write to the register on that module at that speed.  However, the problem comes from the fact that Compact Fieldpoint controller can not access the registers at that speed, so you will not have access to all the samples at that update rate.

For your application, Compact Fieldpoint does not provide the all around performance you are going to need.  Compact RIO is going to be the best solution for you.

Regards,

Kevin H