ASIAIR listens to a couple of Unix Ports for external queries.
For example, ASIAIR listens to port 4030 for iOptron mount commands, port 9624 for LX-200-compatible mount commands, etc.
When a command is received on one of these ports by ASIAIR, ASIAIR passes the command to the mount, and when the mount replies, ASIAIR will pass the result back to the device that is connected to the port. ASIAIR is simply a proxy server for the mount.
The Telescope Setup of SkySafari lets you set up the IP (internet protocol) address of ASIAIR as the mount proxy, with the appropriate port number.
For example, if you set up ASIAIR as a "hotspot" (i.e., access point), ASIAIR's IP address is 10.0.0.1. In this mode, SkySafari is also connected to the same network as ASIAIR. Therefore, you would set SkySafari up with IP 10.0.0.1 and port 4030 if you have an iOptron mount, or port 9624 if you have a n LX-200-compatible mount.
If you set up ASIAIR as station (STN) mode, or if you have connected ASIAIR directly using Ethernet cable to your home network (or an extender of the home network), ASIAIR's IP address will be an address that is given to it by your home network's router. You can find this address on your router's tables, or from the ASIAIR Settings window. For example, if you are directly connected using Ethernet, click on Wired Ethernet, and you should see the IP address.
In my own case, I have ASIAIR (v1) connected directly through Ethernet to a travel router that acts as an extender of my home network. My home router assigns 192.168.7.234 to ASIAIR, and the Wired Ethernet information on ASIAIR also tells me that its IP address is 192.168.7.234.
This is why you should reserve an IP address on your router for ASIAIR to use. This way, you won't need to change SkySafari's IP and Port set up each time the home router assigns a different IP address to ASIAIR.
So, in my case (your IP address will be different, don't blindly use my address :-), I tell SkySafari that the mount IP address is 192.168.7.234. And I tell SkySafari that the port number is 4030 if it is an iOptron mount, or 9624 if it is a LX-200-compatible mount.
When you connect SkySafari to the mount, it will therefore connect to one of ASIAIR's proxy ports.
Once connected to a mount, SkySafari constantly polls the mount (the ASIAIR proxy in our case) to obtain data. For example, with the iOptron mounts, SkySafari repeatedly (non-stop!) sends the # command to obtain the current RA and declination values. This is how SkySafari knows where the telescope is pointed to.
This is why, after a plate solve, you need to sync the ASIAIR RA/declination values to your mount -- so that the mount can in turn tell SkySafari the new RA/declination values.
In short, SkySafari does not know it is talking to ASIAIR. It simply sends the mount commands to the IP address and port that you have given to SkySafari. As the proxy, ASIAIR passes the mount commands and responses to and from the real mount. From what I can tell, ASIAIR also does not know that the mount commands are coming from SkySafari.
Clear skies,
Chen