Telesto Private Wire, Руководство пользователя

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4. Technical Description
Overview of the Hardware
The Telesto Private Wire Modem is the interface at a remote seismic site between the Nanometrics
Europa digitiser and the telephony communications network. The Europa digitises analog seismic
signals, packages and outputs this information in the form of a serial data stream of a proprietary
format. The Telesto modem integrates all the hardware necessary to receive data from the Europa
digitiser and sends these data to the network central site. It also provides for the reverse flow of
data by receiving various network management information from the central site and passing it to
the Europa digitiser. Optionally, the Telesto Private Wire Modem provides power to its associated
Europa digitiser. The general function of the Telesto is shown in Figure 1.
Figure 1: Telesto Private Wire Modem, General Function
Theory of Operation
The two main functions of the Telesto modem are to interface the data from the Europa digitiser to
the leased-line telephony network and, optionally, to supply power to the Europa digitiser. The
functions are performed by a Printed Circuit Board (PCB) mounted inside the Telesto enclosure.
This PCB contains two principal comp onents - a modem and three DC/DC converters. Other
ancillary comp onents include flex circuits which interface the PCB to the Telesto front panel
connectors. The main functions are des cribed below.
Interfacing serial data to the leased-line telephony network
The serial data stream produced by the Europa digitiser uses an RS-232 physical layer protocol.
This format is not suitable for transmission over a leased-line telephone network because of signal
Technical Description
Telesto Private Wire Modem 9
TELESTO
PRIVATE WIRE
MODEM
Optional 12 VDC out (to Europa Digitiser)
24 VDC in (from external power supply)
RS-232 serial data (to/from Europa Digitiser)
Telephony traffic (to/from leased-line telephone network)
POWER
DATA