G11 Preflash mode and z240 type 4

Is there any special setting to use on the G11 for to make the preflash work. The z240 sometimes needs the camera(G11) to shoot with the preflash on. There is no dedicated setting on the G11 that I can find that controls the preflash. On older cameras you can see the preflash, new cameras are much faster so i can not see the preflash.

Questions:

Is the preflash always on?

how do i know the preflash is on?

Is there any test to make sure it is working on land, with or without strobe?

thanks

Pretty sure there is a pre-flash for any TTL-enabled mode ... ie any time the flash is NOT in manual, there will be a pre-flash.