Both options shouldn't be used for fast data acqusition:
Option Force Interrupt Mode: Analog Input doesn't use DMA in this mode. Depending on sample rate, this can help to avoid building blocks of data. Even when block size is set to one, the data can arrive in DASYLab in blocks (e.g. 8 blocks at the same time, then a pause for duration of 8 blocks, then another 8 blocks). This is a disadvantage for applications like PID control. Switching the mode to Interrupt Mode can help to avoid building such blocks, depending on measurement hardware and sampling rate. The option shouldn't be used for fast acquisition as the data throughput is much better in DMA mode.
Option Slow Interchannel Scanning: In default setting, on every sample point the hardware is sampling all channels as fast as possible (e.g. 1 µs between two channels on 1 MHz card), so they are sampled nearly at the same time. When this option is on, the hardware uses almost the complete time (98%) between two sample points to scan the channels (e.g. with 4 channels at 1 kHz it is nearly 250 µs between two channel scans). This can slightly increase the accuracy of the measurement when slow acqusition is used.
