Payment Series (PS)
The Payment Series APIs are offered to you as an integrating Merchant, if you want to manage directly the unscheduled MITs (Merchant Initiated Transactions). The Payment Series would enable you to group your MITs under a known structure, namely a "Payment Serie" and offers additional linked API methods.
Triggering of the MITs could be done on a timely manner when you wish by calling the Create PS Transaction APIs.