ADC arduino - SPI question

Hi all. I'm only just starting to think about using the arduino mega 2560 to do some repeated sampling .... for approximately 1 second with a sampling rate of 2kHz.

I'm going to start with the mega's own ADC (and later with some basic external ADC module -- eg. MCP32XX with SPI interface).

If anyone here has done some arduino projects with external ADC modules with SPI interface, then can I ask you just a few things that can help me with my understanding of the samples that are going to be transferred from the external ADC module to the arduino for temporary SRAM storage?

My first question is..... for repeated (constant rate) sampling, is it a matter of pre-initialising the external ADC module (such as to get it primed and ready for action), and then we send one SPI command to the ADC to get it to do its thing ..... such as to keep sampling and converting and transferring the conversions (in digital codeword form) to the arduino's SRAM?

Am I on the right track by assuming that the external ADC module keeps converting away, obtaining one codeword after another - continuously, and those codewords must get transferred (via SPI) to the arduino without interruptions until the chosen amount of SRAM we want to use gets filled up, right?

Also, I'm assuming that the external ADC module's sampling rate is set up by pre-initialisation (SPI commands from a library), right? So as long as the incoming codewords (coming into the arduino) are received correctly, then we just assume that the sampling period is known too (due to configuring the ADC module's sampling rate via SPI commands), right?

Thanks for all guidance and help in advance!

I think, it depends on the chip used. I sketchily tested a breakout board with I2C PCF8591. There you send the control bytes and the you can ask for value. The sampling starts when control bytes are received and the returned value is perhaps the average of samples taken until the value is transferred. I asked for the value again and again without sending the control bytes and the value appeared to be an average of the values read from the moment I sent the control bytes. I sampled AC with current transformer.

Thanks Juraj. I'm thinking of trying the SPI modules to begin with. I will see how it goes with the MCP3XXX modules after I get one together on a circuit board.