User`s guide

Getting Star ted with RTDX™

a string that does not identify an existing channel in the executable, the

open operation fails.

In this tutorial, two channels exist on the processor —

ichan and ochan.

Although the channels are named

ichan for input channel a nd ochan for

output channel, neither channel is conﬁgured for input or output until you

conﬁgure them from MATL AB software or CCS IDE. You could conﬁgure

ichan as the output channel and ochan as the input channel. The links would

work just the same. For simplici ty , the tutoria l conﬁgures

ichan for input

and

ochan for output. O ne more note—reading and writing are deﬁned as

seen by the processor. When you write data from MATL AB software, you

write to the channel that the processor reads,

ichan in this case. Conversely,

when y ou read from the processor, you read from

ochan, the channel that

the processor writes to:

1 Conﬁgure buffers in RTDX to store the data until MATLAB software can

read it into your workspace. Often, MATLAB software cannot read data as

quickly as the processor can write it to the channel.

cc.rtdx.configure(1024,4); % define 4 channels of 1024 bytes each

Channel buffers are optional. Adding them provides a measure of insurance

that data gets from your processor to MATLAB software w ithout getting

lost.

2 Deﬁne one of the channels as a write channel. Use ’ichan’ for the channel

name and ’

w’ for the mode. Either ’w’or’r’ ﬁts here, for write or read.

cc.rtdx.open('ichan','w');

3 Now enable the channel you opened.

cc.rtdx.enable('ichan');

4 Repeat step s 2 and 3 to prepare a read channel.

cc.rtdx.open('ochan','r');

cc.rtdx.enable('ochan');

5 To use the new channels, enable R TDX by entering

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