First of all, you would need to program your scanner in the trunking mode. Your manual would show you how to do this. You will need to go to the RR database and find your county tower frequencies. You will need to put in all frequencies for your scanner to work. Then follow the manual on how to enter the Talk Group ID's. These are the hex and dec. You will want to put in the hex number.What I don't understand is why next to the park police in the list it shows a hex and a dec number. But no frequency. I don't get what frequency I have to add to hear the park police only. I'm a noob when it comes to this while trunking thing.