My article explains exactly how to do what you're describing:
https://www.reef2reef.com/ams/neptune-apex-programming-tutorials-part-7-feed-cycles.715/
Here's the relevant part:
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The best way to incorporate an automated feeder and mimic the Feed Cycle buttons is to use a virtual output to control everything. Here’s an example:
Virtual Output vFeed:
Set OFF
If Time 08:00 to 08:02 Then ON
If Time 17:00 to 17:02 Then ON
Defer 005:00 Then OFF
AFS Output Configuration:
Fallback OFF
Set OFF
If Output vFeed = ON Then ON
Defer 001:00 Then ON
Return Pump Configuration:
Fallback ON
Set ON
If Output vFeed = ON Then OFF
Skimmer Configuration:
Fallback OFF
Set ON
If Output vFeed = ON Then OFF
Defer 005:00 Then ON
Now when the vFeed output is set to AUTO, it will turn on at 8am and 5pm for 2 minutes each. This will cause the return pump and skimmer to turn off immediately. The AFS feeder will wait 1 minute (due to the Defer timer) and then make a single rotation. One minute later the vFeed output turns off, so the powerheads and return pump come back on immediately. The skimmer waits an additional 5 minutes due to the Defer timer, allowing the sump water level to return to normal. Just like the manual Feed Cycle buttons, but all unattended!