Hi @lucas_stepwise, we are excited to have you on the forum!
Is the signal moving inbound (Notehub → Notecard) or outbound (Notecard → Notehub)?
If it’s outbound, that’s easy. You can leave in it periodic mode and add the "sync":true parameter to note.add. It will only use the resources necessary to send the data on demand.
If it’s inbound, that’s a little more tricky. If you want the message instantly, then you must be in continuous mode with the "sync":true parameter added to hub.set. sync will create an open socket to the Notehub, that will instantly inform the Notecard it has a message waiting on Notehub and should perform a sync. This is the fastest and most resource intensive option. If you are happy with a cadence (5 minutes), then you can use continuous or periodic with an inbound interval.
periodic vs. continuous - Determines whether or not you will need to turn on the modem and establish a connection to the tower or just leave it connected at all times.
sync - is the parameter that can be applied to lower latency.
I would suggest playing with the different combinations to get a feel for what behavior meets the need of your application, then maybe getting an ammeter and monitoring current consumption so you can tailor any final decisions to the resources you have available.
Best,
Zak