When sourcing a sequential controller, you must prioritize timing accuracy and channel capacity. Ensure the device supports the required number of output channels (typically 8, 16, or 32 channels) for your specific application, such as dust collector pulse valves or power sequencing. Look for controllers with adjustable pulse width (0.01s - 0.99s) and interval time settings to optimize system performance. Additionally, verify the input/output voltage compatibility (e.g., AC220V or DC24V) to match your existing hardware.