Monitor vibration over long distance (>300m)

[PQH]

Hi everyone,

Currently, I have a project to monitor vibration (16 IEPE channels) from a station that is more than 300m away from monitoring station. Looking at NI's products, I have a few options:

1. Using ENET-9234:

- Only 4 channel/module. I need to use 4 modules in total, and need to connect to a router.

- Ethernet distance is limited at 100m. To reach 300m, I need to use at least 2 repeaters, which are not suitable for my project (off-shore environment)

2. Using MXI-4 with Fiber Optic: PXI-8336

- Maximum allowed distance is 200m.NI recommend to add another segment (i.e. add another PXI chassis in between) to extend range to 400m. Or use optical converter to convert between multi-mode fiber to single-mode fiber to extend range

http://digital.ni.com/public.nsf/allkb/C86BF63CC73C6721862575F2005A246D

These recommendations are not suitable either due to harsh contion in the sea and difficult maintenance.

3. Last option is acquire and process data at the site. Then transfer only processed data back to monitoring station over GPIB or RS-485.

I would like to seek your advices on these options. Is there any way to avoid the repeaters in between?

If you have any other ideas, please kindly let me know.

Thank you very much!

Have a great week ahead!

PQH

[Henrik_Volkers]

I would take look at a cRIO system. And would think of maybe include some resolvers for the engines. (order analysis)

There you can make both: send out raw data and have a fall back system that could run stand alone .

Since there are industrial fiber solutions for Ethercat (2km?) there should be also some for Ethernet 😉

(My guess wold be that you can make 300m @10Mbit with a high quality cable and since you get the cRIO with a RS485  you have a fall back and use the copper for the current loops)

[preston_johnson]

I also like the cRIO approach.  There are copper to fiber media converters on the market that offer single mode fiber which is what you would need for the longer distance. 

Check out the following tools to help you get up and running quickly with cRIO:

This listing is an attempt to list and briefly describe core tools that speed the development of waveform acquisition and analysis applications on the CompactRIO and RT platforms. 

 

NI CompactRIO Developers Guide: This is a core developer's guide for a wide range of waveform acquisition and analysis applications.  It provides useful background on CompactRIO and control applications in particular.  It has chapters on waveform acquisition as well as deployment and management of applications on CompactRIO. 

http://www.ni.com/compactriodevguide/

 

Reference Applications for cRIO Waveform Acquisition:  This is the core template for acquiring waveforms for analysis, including vibration, electrical power, and structural monitoring.  It makes a great starting point for waveform applications on cRIO. 

http://zone.ni.com/devzone/cda/epd/p/id/6206

 

cRIO Reference Designs for Structural Health Monitoring:  This reference builds on the waveform acquisition reference and adds scan engine for slowly changing signals as well as TDMS data logging on event.

http://zone.ni.com/devzone/cda/tut/p/id/9851

 

Simple Messaging Reference Library (STM): This tool provides a TCP/IP communications protocol which is used in the benchmarks shown on the waveform acquisition reference page.  It is an excellent tool for efficient communications between cRIO and a host, easily supporting time waveform live streaming.

http://zone.ni.com/devzone/cda/epd/p/id/2739

 

Reference Library for Converting Between LabVIEW and XML Data (GXML):  This reference provides a remote XML configuration tool, to be used for remote configuration of the cRIO LabVIEW application.

http://zone.ni.com/devzone/cda/epd/p/id/6330

 

LabVIEW Syslog Protocol Reference Library: This reference offers a UDP cRIO status monitor to indicate to the host the operational status of the remote cRIO

http://forums.ni.com/ni/board/message?board.id=Components&thread.id=51

 

Reference Applications for cRIO Order Analysis Using a High Speed Tach:   This reference offers tachometer or encoder interpretation in FPGA when the I/O device is in a separate and higher speed loop. 

http://zone.ni.com/devzone/cda/epd/p/id/6301

 

DSA Module Synchronization Reference Design for Multiple cRIO Chassis:  This reference is useful when the timing of I/O needs to be tightly synchronized between two cRIO chassis.  It works with a signal line, as well as with GPS. 

http://zone.ni.com/devzone/cda/epd/p/id/6146

  

Additional NI Systems Engineering Components are listed here:  Additional tools can be found on the Systems Engineering Components discussion forum. 

http://forums.ni.com/ni/board?board.id=Components

Hope this helps you get started with cRIO, which is a great choice for industrial oil platform applications for temperature, and Class 1 Div 2 certifications. 

[PQH]

Hi Henrik and Preston,

Thank you very much for your suggestion.

I intend to use NI 9234 in cRIO for this application.

This is an off-shore application so I took a look at the list of NI products that are LR Marine Approved

http://digital.ni.com/hardref.nsf/webmarinestds?openview&node=132110_US

One funny thing is that, almost all cRIO products are LR Marine Approved except NI 9234. Do you know the reason why? And is it getting certified any time soon?

One again, thank you very much for your valuable advices!

PQH

[GarPar]

Hi PQH-

     The marine certification process typically takes place after adequate customer interest.  I am unsure about whether or not the 9234 has been submitted for marine certification, but I have noted your interest and will relay that information to R&D.  I will let you know what I find out.

[GarPar]

PQH-

     I have spoken with R&D and it turns out that the 9234 is not LR Marine Compliant.  If your application requires LR Marine Certification, the spreadsheet you linked above contains all of the modules that are certified.

     Best of luck with your application!

[preston_johnson]

there is a vibration module that IS marine certified - that is the 9233 - so that is a good one to use.  It has IEPE on all the time and is AC coupled all the time. 

We are beginning development of an additional IEPE module that should have the characteristics to be Marine certified. 

Preston