I've attached an example screen capture of how I set up TAC310 in my Anytone D878. A few things to note...
* The channel name begins with HS. I use that naming convention to identify it as a Hotspot channel.
* The receive and transmit frequencies are the same. Use some care here in selecting frequencies that are not in conflict with public use frequencies in your state / local area. These frequencies will also be programmed into the OS2 on the Modem page | Frequency.
* Use Low power.
* Band Width is 12.5K
* TX Permit is Different Color Code
* The Receive Group List is Hotspot. I created this Receive group list to include TG9 so that messages transmitted by the OS2 will be heard on the Anytone.