interfacing matlab with real time system

i want to interface MATLAB with my project for real time application, but confused what to use , xPC target or Real time windows target? please tell me what procedures to be followed?
thank you

Answer 1

[Walter Roberson]

Some essential questions you have to answer are: How quickly does your system have to notice that an event occurred; How quickly does your system have to react to the event; What is the allowed variation in response time; and What is the peak rate at which events can occur.

If you need a very short response time, or high peak rate, or you need a fixed guaranteed maximum response time to deal with an event, then chances are you are going to be driven towards an embedded system, possibly with specialized I/O.

There are a number of systems which are really only "pseudo-real-time" -- systems that just have to most of the time reply within the patience of a human. Especially when the load is not heavy, you might be able to handle the system within basic MATLAB without even RTWT.

[shahid khan]

my system must be able to response to speech signals.i want to store digitized speech data in the matlab for filtering, recognizing speech then converting it in the form of pulses until my system is on. the processed data again give to another system.the allowable time for storing and processing speech signal of 5sec at low bit rate,is 10sec. is it possible?? or it will take more time to process?? i'm using matlab R2009a on amd sempron 64-bit 2.2 Ghz cpu. and how can i handle my system without RTWT for any other application. thank you.

[Walter Roberson]

telephone quality speech is 8000 samples per second, with 8 bits per sample, for a total of 64000 bits per second. Your system should have no problem reading 8K per second of mono through a microphone attached to a basic sound card.

You indicate that the processed data has to be sent to another system. If the time to do that is included in the 10 seconds, then you need to figure out how much data is being sent to the other system and how quickly it can realistically be sent, and subtract the time from the (10 seconds minus 5 seconds) to get an idea of your time budget. If it is _all_ being sent out through a similar 8000 samples/second 8-bit channel (e.g., filtered sound) then that will take another 5 seconds, and your processing time budget is down to 0 seconds -- unless, that is, you are able to overlap the data acquisition with the processing.

You mention about "recognizing speech" but you do not mention anything about which speech recognition algorithm you hope to use, so we do not know if you need to read in the full 5 seconds before you start processing or if you can start processing earlier. If you do start processing earlier than you will need to use a "windowed approach": that is, rather than chopping the sound at (say) 0.1 second boundaries and processing each independently, you will need to allow groups of segments to be used together.

[shahid khan]

will u please suggest me how can i read data say temprature at some interval like 0.5sec from real world to matlab. what type of hardware are required to do that which i can connect to my PC? i have heared about arduino, is it possible to do this with it? please help me, i'm new to matlab.

thanks in advance.