EXTERNAL MODE ON TI C2000

Hi I am using external mode to run a simulink model on TI F28335, I am trying to log some data on the scope by triggering it only for 20 ms , unfurtunatily I am not able to get more than 140 samples, when I increaee the duration for 150 for example it shows this message on command windw ''action: EXT_SELECT_SIGNALS Got EXT_SELECT_SIGNALS_RESPONSE from target with status NOT_ENOUGH_MEMORY'' , by the way the sampling frequency in this model is 50 microsecond. could any one help me to get more samples

Answer 1

[Sriram Narayanan]

This warning is thrown by the target when Simulink downloads the signals that must be logged. There are a few reasons why this might be thrown.

One of them is that the duration is large and the target is trying to allocating too much memory based on the size of the duration. There is no upper limit to the duration, it is dependent on how much memory a target has. For a PC, the duration can be huge. For embedded targets, it depends entirely on how much memory can be allocated.

It is possible the duration is set to a reasonable size for the target and this warning is still thrown. If there are many, many signals being logged, then the amount of memory being allocated may be too much even though the duration is small. So another possible solution is to decrease the number of signals being logged.

[Mohamed Ahmeid]

Thank you for your answer, you mentioned that the duration depends on how much memory a target has for a PC, for the target I'm using how do I know this part of memory in order to expand it ?

[Walter Roberson]

number of channels multiplied by samples per second multiplied by number of seconds multiplied by bytes per sample. (Note: some embedded processors use 16 bit bytes.)

[Mohamed Ahmeid]

As you know TMS320F2335 has external and internal memory , which one of them I can modify to collect more number of samples in scope in external mode?

[Walter Roberson]

external memory.