Hi Alexandra,
If you issue the SDATAC command, there is no need to issue a delay between commands. The stretched clock and the 25 clocks instead of 24 will cause you many issues. The SPI interface for the ADS1248 works in byte sequences. A stretched clock confuses the state machine. Another confusion occurs when you issue 3 bytes of clocks and then issue another clock. This has the similar effect of stretching the clock but in a major way as the 25th clock relates to the next byte sequence. We have no idea what data is sent back or how the internal buffer of the ADS1248 is being loaded. The best case scenario is you shift the data by one every read cycle. The commands are lost as well as the data because of the clock shifting. Toggling CS will remedy this problem as well as sending the correct clocking pattern. If you tie CS to DGND, then you must make sure you are sending the correct number of clocks to represent the data you are communicating.
Best regards,
Bob B
