Chapter 2: 2-8 Control Head (CDM1250 / PRO5100 / CDM1550 Series / PRO7100)
6881091C63-A
3.11 PassPort Trunking Controller Board (PTCB)
PassPort is an enhanced trunking protocol developed by Trident Microsystems that supports wide-
area dispatch networking. A network is formed by linking several trunked sites together to form a 
single system. This offers users an extended communication coverage area. Additionally, users with 
PassPort can seamlessly roam among all sites within the network. Seamless roaming means that 
the radio user does not have to manually change the position on the radio when roaming from site to 
site. 
For models which feature PassPort Trunking operation, the PassPort Trunking Controller Board 
(PTCB) is added to the top cover of the radio. This board also provides advanced voice storage 
features. Refer to Figure 2-1 for connector and signal routing from and to the radio and PTCB.
Figure 2-1 Full Serial Interface Lines for PassPort Trunking Controller Board
PassPort Board
Main Radio Board (68HC11)
J601-26
J601-25
J601-38
J601-12
J601-11
Serial Data Send Serial Data Return
Serial Data Return Serial Data Send
Serial Clock Send Serial Clock Line
Data Ready/Request Data Ready/Request
Option Board Enable Option Board Enable
Voice Storage
J601-6 J601-10
Flat Tx Return
Flat Rx Send