| 摘要 |
In order to enable local time metering in conventional switching systems (system 55, system F6/F6a), an ancillary meter (ZZ) is inserted in the selection stage (I.GW, ORW and UGW) suitable for this purpose. After receiving the answer signal, this meter receives the metering clock signals supplied by a clocked unit (TG) and, following suppression of the first periodic metering clock signal, forwards them via the metering wire (za) to the meter of the calling subscriber. Once the clearing signal has been received from the called subscriber, unless the calling subscriber hangs up, the call is cleared down after a specific delay period. Depending on the respective system, either the so-called answer pulse or a pulse generated with the clearing signal is recorded as the meter pulse. The functional procedures required by the different operating cases are controlled according to the switching states of two relays (S, X). The ancillary device is not activated when a long-distance call is set up. <IMAGE>
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