Kontron 104-422-2I, Руководство пользователя

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Overview 1-3 104-422/485-2I User’s Guide
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Overview
The 104-422/485-2I serial communications card is designed for use in PC/104compatible
computers. Two serial data ports are provided on the 104-422/485-2I.
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Multipoint Opto-isolated
Communications
The 104-422/485-2I allows for multipoint transmission on long communication lines in noisy
environments using RS422 or RS485 differential line drivers. The data lines are opto-isolated
from the computer and from each other to assure communication when large common mode
noise are superimposed. The on-board DC-DC converters provide isolated power for the line
driver circuits.
A crystal oscillator is located on the card. This oscillator permits precise selection of baud rates
from 50 to 115,200. Baud rates up to 460,800 baud may be provided as a factory option. The
Programming section of this manual contains a table to use when selecting baud rate.
The output transceivers used, type 75176B, are capable of driving extremely long communication
lines at high baud rates. They can drive up to ±60mA on balanced lines and receive inputs as low
as ±200mV differential signal. Opto-isolators on the card provide protection to maximum 500 V.
In case of communication conflict, the transceivers feature thermal shutdown.
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COM Port Compatibility
Type ST16C550 UARTs are used as the Asynchronous Communication Element (ACE) which include
a 16-byte transmit/receive buffer to protect against lost data in multitasking operating systems,
while maintaining 100 percent compatibility with the original IBM serial port.
You can select a base address anywhere within the I/O address range 000 to 3E0 hex.