| 摘要 |
A dialling discriminator which may be connected to a receiver unit and which is adapted to distinguish between incoming decimal and arrythmic dialling signals. A first polarity sampling is made 130ms after the receipt of an incoming signal. If the sample is negative then decimal dialling is indicated since arrythmic dialling, by definition, is always positive at this point. If the sample is positive, however, no decision can be made and a second polarity sample is taken at 160ms. If this second sample is negative then arrythmic dialling is indicated, since same is always negative at this point while decimal dialling is always positive. |
