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#11174 - 09/27/11 09:13 AM RIO-Analog i/p capture frequency
sams1982 Offline
Junior Member

Registered: 03/26/08
Posts: 13
Hello,

I am using RIO47122 Controller for data acquire purpose.
I want to know what is the maximum Analog I/p data capture rate or frequency of RIO-47122...????

Thanks,
Sameer.

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#11180 - 09/27/11 04:17 PM Re: RIO-Analog i/p capture frequency [Re: sams1982]
MarissaT Offline
Member

Registered: 06/23/11
Posts: 245
Loc: Rocklin, CA
Hi Sameer,

Could you specify more specifically what you mean? For instance do you want the maximum read time for the A/D converter chip itself, or what one would see as normal behavior for the RIO as a full product (from command to reading input)?

Also, how are you using the inputs for your application? For instance, there may be different specifications depending on how you plan on acquiring the data. In terms of sampling time; If one chooses to use the optional PID loops on the RIO, an update rate of 1ms is default, but can be changed using the CL (control loop command). If one uses the automatic RD (Record) option the maximum sampling time is 2ms (also can be changed using the RD function). If one is simply using the @AN[X] command to obtain a single sample, this too would have it's own rate.

Let me know,
_________________________
Marissa K Tucker
Applications Engineer
Galil Motion Control, Inc.

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#11181 - 09/27/11 09:26 PM Re: RIO-Analog i/p capture frequency [Re: MarissaT]
sams1982 Offline
Junior Member

Registered: 03/26/08
Posts: 13
Hi Marissa,

Thanks for your feedback.

I would like to know -
1) Maximum read time for the A/D converter as well as the Max read time from command to read the analog I/P.

About my application, I want to use Analog I/p to capture the distance which is continuously varying during process(Here I am using Non contact type of LVDT which gives us an O/P 0-5 Volts corresponding to the distance measured.After that if the distance value measured is greater or less than the required distance then program will change the polarity of one Analog O/P ).
Maximum rate of change of analog I/p is 3khz..

I am not using PID loops in the program nor I am Recording the data.

Thanks,
Sameer.

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#11188 - 09/29/11 08:54 AM Re: RIO-Analog i/p capture frequency [Re: sams1982]
MarissaT Offline
Member

Registered: 06/23/11
Posts: 245
Loc: Rocklin, CA
The analog input is on demand, meaning the maximum read time from command to reading the analog input is going to be dependent on your specific application. Things that can effect the time to reading the analog input include communication overhead, number of threads running, update rate (set by TM), data record output rate, etc. will all effect this time.

To talk more about the specific applications to narrow down what you would expect, e-mail me at marissat@galilmc.com


Edited by MarissaT (09/29/11 04:50 PM)
_________________________
Marissa K Tucker
Applications Engineer
Galil Motion Control, Inc.

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