| 摘要 |
<p>There is provided portable survey apparatus comprising a 20-core cable terminated on an interface module. One of the conductors is designated as common. Sixteen of the remaining conductors are designated as data lines 1 to 16. Spare conductors are designated as a diagnosis pair. Data conductors are each terminated at the inner conductor of an RCA connector spaced along the cables, the shield or ground thereof being electrically connected to the common conductor, the connectors being securely maintained in position aligned parallel to the cable axis. Drop leads having one end terminated in a corresponding connector are thereby adapted to engage the cable, the other end being terminated in a thumb-operated normally closed, momentary type microswitch. An interface module comprises a substantially sealed enclosure connecting the cable and a port for connection to a PC. The PC is used to generate a multiplex digital signal essentially comprised on an identity bit from 1 to 16 and a value of 0 or 1. A demultiplexer converts this data to a pin assignment and a pulse. The demultiplexer continually pulses each data line. When the interviewer puts a proposition one or more of the candidates will press the microswitch resulting in the data line corresponding to the person going open circuit that will be recorded as an event attributable to that data line, as well as recording the same or null events for the remaining data lines. The data collected has relevance to both identity and value.</p> |
