There are a couple of priority scanning "things" with the x36 scanners. They are two separate and distinct creatures when it comes to conventional and trunked priority scanning. One has to look very closely at the the wording and it takes some getting used to. I'll summarize a little below, but there is a detailed explanation in the manual starting on page 50.
"Priority Scan" applies to conventional systems. "Priority Scan" is enabled in Sentinel by editing the applicable profile (Miscellaneous>Priority Scan Mode either DND or Priority). Then in the Favorites List Editor, desired priority conventional frequencies (channels) are marked with P-Ch On.
In "Priority Scan", when the scanner stops on an active non-priority conventional frequency (channel), it will periodically check those priority conventional frequencies (channels) for activity. If there is activity, the scanner holds on the priority. When checking for a priority conventional frequency (channel), it is pretty apparent as there is "skipping" in the non-priority transmission.
For a trunked radio system, it is called "Priority ID Scan". Upman described how this works. "Priority ID Scan" is something set up entirely within the Favorites List Editor for the applicable system. In the applicable system, go to the Options tab and choose On for the Priority ID Scan and then selected the desired Talkgroup IDs by turning P-Ch On. Priority ID Scanning of trunked systems is not as obvious as Priority Scanning of conventional systems. There isn't that interuption.
A couple more things to note:
If you are scanning both trunked and conventional systems and the scanner is holding on an active convention frequency, it does not look at a trunked system for active talkgroups that are set for priority.
Conversely, if holding on an active talkgroup in a trunked system, the scanner does not check for an active priority frequency in a conventional system.
If you have turned Priority Scan On (the one for conventional systems), the scanner has to have "access" to at least one conventional freqiency (channel) marked as priority. If it does not have that "access", then the message "Priority Scan. No Channel" is displayed. "Access" to priority conventional frequencies (channels) can be denied in several ways: The applicable FL turned off, system/department/channel avoided and so on.
If you see that "Priority Scan. No Channel" message, you can press System to resume scanning and the scanner will re-set Priority Scan to Off. To go back into Priority Scanning you have to restore access to priority channel(s) and turn Priority Scan back on to either DND or Priority.