This what a typical time-motion diagram for ACH looks like.
For data fields etc see this answer and the links within it: How does an automated clearing house (ACH) work? How does it process payments, and how is it different from RTGS (which are used to process low-volume, high-value transactions), or other localized financial networks and switches?
For data fields etc see this answer and the links within it: How does an automated clearing house (ACH) work? How does it process payments, and how is it different from RTGS (which are used to process low-volume, high-value transactions), or other localized financial networks and switches?