Yes, they are DC modules, so you would want to use the GetClearAnalogMaxValue command to see when the “DC voltage” is above a threshold - You can think of the 24VAC signal as a DC signal that is changing between approximately -34 and +34VDC. So if you see the max or min voltage change to those values, then you know the input is on.
Since the step change on that module is pretty slow, I would expect some seemingly random values when the signal is on - I would recommend testing that to see if it will work in your application - you may need to use a fairly low voltage for the threshold and turn off any signal averaging (SMA) since it would tend to average towards zero volts. The module also has some hardware input filtering that may work against you. A series diode may be needed if the filtering is too much to keep the voltage positive.
This is just an idea, and would need to be tested to see if it would work. I don’t have one of these modules or I would test it for you - maybe @Beno has the equipment available to throw together a quick test.