How to marry solar and genset

Welcome to the forum Daguinn,

I am not clear what your question is... A DLS-30-IQ4 is a 120 VAC to 12 VDC power supply/battery eliminator/battery charger.

https://www.solar-electric.com/iota-engineering-dls-30-iq4.html

A typical 120 VAC output generator would connect to the 120 VAC input of the Iota. And the 12 VDC output would typically connect to the 12 volt battery bus (with appropriate wire size, length, routing, insulation, fusing/breaker, etc.).

Other 12 volt current sources (solar charge controllers, vehicle house battery charger, etc.) would also attach to that same 12 volt battery bus (correctly/safety/etc. connected).

More or less, each charging device (battery charger, solar charger, etc.) would measure the battery bus voltage (some also measure time on charger, charging current via a precision power resistor/shunt) to determine when the battery is "full", drop back from "agressive/active" or Absorb Charging (i.e., 14.4 to 14.75 volts on battery bus or so) when charging a discharged battery, down to "float" voltage at 13.6 volts or so to keep battery bank charged and make up for other loads (keep battery at 13.6 volts until sun sets, generator is shut down, etc.).

Where this can get more "complicated" is that wide variety of solar/off grid/battery based devices out there--Not just a simple 12 volt lamp or 12 VDC to 120 VAC inverter--But various combination devices (inverter-charger-solar controller-generator automatic starter, etc.)... And add the LiFePO4 lithium ion batteries + BMS (battery management system) to ensure proper charging of a Li Ion bank, and avoid over/under voltage/over current/running outside normal operating temperature, etc.)...

If you have a relatively standard power system--All of the 12 VDC devices attach to the battery bus. It is OK to parallel multiple sources (chargers) and sinks (loads) to the same bus and let each control its own operation.

There are "edge cases" that you need to worry about, especially with Li Ion/BMS system where it is very possible to have Solar Noon charging current + Iota charging current exceed the rated battery charging current (i.e., 50 amp max rated Li Ion battery, and two 30 amp chargering sources = 60+ amp charging current--Which damages the Li Battery and could trip the BMS safety circuit--Another issue to "reset" the BMS for example).

Details matter here (for safety)... Does this stuff make sense?

-Bill