question

You should try to use Process Flow!!!

If you let travel a transporter to an object, neither the object nor the transporter knows that the transporter has arrived. You can check if the location of the transporter is near the coordinates of the object, if the transporter gets available. Or you can send a message from the tasksequence the transporter does, to an object to notify that travel task to an object is done. I have given this answer already in the answer to question send message! If you need a transporter at an object that does nothing then you can misuse him by using him as operator for processing. Please look for the keyword "tagged resource" to use the same transporter later to transport the item of the processor.

But as I have written above please consider to use Process Flow. There are some activities that you can combine that let pass a token to the next activity if some conditions become true. Process Flow let you build a logic similar as you would describe the conditions in your own words. And please do the tutorials in the manual of the program. And perhaps you are allowed to use the latest version of Flexsim then please use this version. There are more and better tutorials and there are some features that makes the modelling easier.