@ashokkumarg I don’t understand what you mean by trigger. Please elaborate a bit more.
When working with multiple host machines it works the same as in single host machine. Launch Appium server for each device and then connect to the Appium server from client with http://<HOST_IP>:<APPIUM_PORT>/wd/hub. When working with single host the HOST_IP address is localhost or 127.0.0.1. In multi-machine setup it is something like 192.168.100.1.
I cannot remember does Appium listen connections from other addresses than localhost by default. If not you can use -a / --address flag to make it listen connections from outside.