Hi Henry,
The frequency pulse appears to be every ~200ms or ~5Hz. I think this would have to be coming from an outside source.
Could you provide us with more details...
- What are you measuring in the above screenshot (where are you probing)?
- What is connected to the ADS1255?
- What type of testing environment is the device in, is this on a breadboard or are you using the ADS1256EVM?
- Do you have a schematic you could share?
Best Regards,
Chris