The PLECS TI C2000 Target Support does not require the user the explicitly set any SOC settings.
The behavioral description of the ADC is as follows, taken from the “Control Task Execution” section of the TI C2000 manual.
“ADC triggers configure the ADC start-of-conversion. The ADC start-of-conversion is driven by an interrupt from either a PWM carrier or the CPU Timer. All ADC channels associated with the ADC unit are converted sequentially when the ADC trigger is activated. The order of conversion is based on the order of the analog input channel vector.”
In practice this means that the ADC SOCs are triggered sequentially. If you review the generated *_hal.c file you can see comments indicating how the SOCs are configured for each ADC channel.