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Serial Interfaces
1.5.2 The RS-232 Interface
The interface controller DUART 68681 processes tranmsit and receive
signals of TTL level. The interface to V24 or RS-232-C respectively,
is realized by integrated level transformers MC1488 (transmitter)
and MC1489 (receiver). Both components are located on the board
below the corresponding DUART.
1.5.3 The TTY Interface
The current loop interface is located behind the V.24 voltage inter-
face, i.e. the V.24 level is transformed into 20 mA current level to
be transmitted. Current loop receive signals are transformed vice
versa. The current loop signals are electrically isolated from the
VMEbus to fulfill the requirements of process automation. (When
’using’ the electrical isolation the power supply of the TTY inter-
face must be supplied externally.)
The current loop transmitter consists of a switched constant current
source. Beside a constant current source the receiver contains a
Schmitt-Trigger for the signal preparation and for noise suppres-
sion.
The VME-ASIO16 current loop interface is designated as "non isola-
ted", because all necessary current sources are located on the
board; thus the process section must not be equipped with current
sources!
VME-ASIO16 Rev. 1.7
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Содержание VME - ASIO16
Страница 1: ...VME VME ASIO16 ASIO16 16 16 serial serial Interfaces Interfaces VME ASIO16 Rev 1 7 ...
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Страница 9: ...Overview 1 Hardware 1 1 Block Diagram Fig 1 1 1 Block Diagram of the VME ASIO16 VME ASIO16 Rev 1 7 5 ...
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Страница 59: ...Front Panel 3 4 Front Panel VME ASIO16 Rev 1 7 55 ...
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Страница 63: ...Data Sheets 3 6 Data Sheets The data sheets are not included in the PDF file VME ASIO16 Rev 1 7 59 ...