LTR and PassPort controllers have a number of adjustable timer settings:
- Idle Timer: controls idle bursts; 10 seconds is fairly standard for LTR home channels; 1 or 2 seconds is typical for PassPort home channels and collect channels - the fast rate is required for roaming (you can't switch to a site if you can't hear its carrier, and you ain't gonna do a strongest site search if you have to sit on each channel for 10 seconds); non home/collect channels on LTR and PassPort systems don't need to send idle bursts (Idle Timer = 0), but some operators just turn them all on
- CWID Time Interval: sets ID period; may only be legally required on one system channel, some operators enable it on all channels; the CWID character string is defined in a separate parameter
- LTR/PP Lead-in Timer: delays sending of low speed data until transmitter has stabilized after keyup; typical values are 200 to 500 ms; when timer is set too short, idle bursts get truncated and can't be decoded
There are other timers, like carrier loss delay (maintains comm during brief RX fades), PTT timer (how long a subscriber can transmit before being muted/isolated), ...