TRANSCEIVER PROGRAMMING
also the type of priority channel (see the “Priority Channel” description which follows). The following modes are available:
No Priority - Priority sampling does not occur (all channels are scanned in sequence). The radio trans- mits on the selected channel.
Priority/Tx Priority - Priority sampling occurs and the priority channel is the one programmed in the selected scan list. The radio transmits on the priority channel.
Priority/Tx Selected - Priority sampling occurs and the priority channel is the one programmed in the selected scan list. The radio transmits on the selected channel.
Priority on Sel Chan - The priority channel is always the selected channel (even if the scan list is programmed with a priority channel). The radio transmits on the selected channel.
Talkback Scan - No priority sampling occurs (even if the scan list is programmed with a priority channel). The radio transmits on the channel of a call while scanning is halted. Then when scanning resumes, it transmits on the selected channel.
Scan Timers
Scan Hold Time - Sets the delay that occurs before scanning resumes after a signal is no longer received (see Section 2.3.11).
Lookback Time A - This time determines how often the priority channel is checked for activity. Times of
Lookback Time B - This time determines how often the priority channel is checked once an incor- rect Call Guard (CTCSS/DCS) code is detected. Since it takes much longer to detect an incorrect Call Guard signal than a carrier, this time should be relatively long to prevent the interruptions from making a message difficult to understand. Times of
Priority Channel Selection
The Scan Mode parameter in the preceding Conventional System Scan List screen selects if priority channel sampling is enabled on the selected scan list. It also selects the type of priority channel (either fixed or the selected) if applicable.
If the “Priority/Tx Priority” or “Priority/Selected” mode is programmed, fixed priority channel sampling is selected. The fixed priority channel must then be chosen for the scan list. To do this, click the 
button in the preceding Modify Scan List screen and then select the desired zone/channel. Refer to Section 2.4.12 for more information on priority channel sampling.
3.5.3SETTING UP CONVENTIONAL CHANNELS
The conventional Channel screen shown in Figure
The general procedure for setting up a conven- tional channel is as follows. Refer to the descriptions which follow this procedure for information on the parameters in the channel screens.
1.Make sure that the desired zone is selected in the Zone box.
2.Select the channel number in the Channels Index box which is to be programmed with the channel. If the channel number display mode is selected (see Section 2.4.2), this will be the number displayed when the channel is selected.
3.To assign a conventional channel, select “Conven- tional” as the channel type.
4.Click the Modify button to display the screen which enables that channel and programs the alias (tag) and transmit and receive frequencies. Then program the other parameters in the main part of the screen. Refer to the next section for more information.
| November 1999 |
Part No. |
