CTI Products TSAM Transmitter Steering & Audio Matrix - Manual (Page 21)

TSAM Installation and Maintenance Rev. 2.10 Chapter 2
CTI Products, Inc. Main Channel Operation
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2.5.6 Console Priority with Repeater Systems
In a typical transmitter steering repeater system, a transmitter is keyed from two different sources.
Detection of a received signal will key a transmitter so it can be "repeated", and the systems dispatcher will
key the transmitter from the dispatch console. In many systems, it is required for the dispatcher to have
priority access to the steered transmitter.
Figure 4 TSAM Console Priority Connections
To provide console priority, an external audio switching relay is added as shown in Figure 4. The console
PTT line is connected to the C1PTT input of the TSAM. Note there is no PTT connection from the
receiver comparator. This is because the TSAM monitors the comparators vote indicate lines and
generates an internal repeater PTT when vote activity is detected.
Since priority is given to console PTT, the TSAMs keying is different when a console keys than when a
repeater PTT keys. These differences are as follows:
• There is no hang time generated when the console unkeys.
• Force Site selects cannot be made while the console is keyed.
• Resteering during console PTT in normally disabled.
If a Force Site Select is activated during a repeater PTT, the current transmitter is immediately unkeyed
and the forced transmitter is keyed. Depending on the timing requirements of the system base stations, a
small portion of a transmission is lost while a station is unkeyed and a new station keyed. If a Force Site
Select is activated during console PTT, it is ignored.
Since resteering during console PTT is normally disabled, any receive activity that occurs while the
console is transmitting will not effect transmitter steering. With resteering enabled during console PTT,
receive activity that steers to a new site is remembered and the new site is updated when console PTT is
released.
Application Notes are available to describe Console Priority with a number of other comparators.