Calling a registered frequency when the Automatic frequency Selection function is not used. This example calls a frequency channel 01.
不使用自动频率选择功能时，调出已登记的频率。该例调出01频道的频率。
2
Calling a registered frequency when the Automatic frequency Selection function is not used.
不使用自动频率选择功能时，调出已登记的频率。
3
In order to improve the ringing method of telephone used in power systems, a type of selective calling device using audio frequency has been developed.