Autogating - Brainboxes CC-346 User Manual

This chapter details the specifications of the PCI quad RS422/485 card and
explains how to configure the RS485 Multiplex jumpers present on both cards.
These half-sized cards will work happily in any PCI 2.0 or greater compliant PC
compatible.
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Four independent 9 pin D RS422/485 Serial ports.
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Reliable communications up to 4000 feet, 1.2 Kilometres.
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16950 FIFO provides 128-byte input and 128-byte output buffer on each
port.
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Maximum baud rate of 912600 Baud (1 Megabaud).
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Word length of 5, 6, 7 or 8 bits.
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Even, Odd, None, Mark or Space parity options.
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1 start bit always sent.
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1, (1.5 for 5-bit data word length), or 2 stop bits.
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TXD, RXD, RTS, and CTS signals.
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RS485 TXD/RXD multiplex selectable by jumpers: - either FULL
DUPLEX or HALF-DUPLEX.
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Fully double buffered for reliable asynchronous operation.
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High-speed integrated circuitry ensures operation with fast PC's e.g. 800
MHz Pentium II WITHOUT extra wait states.
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Autogating low level RS485 half duplex (2 wire) control
Clock Input:
Drivers:
High Level Voltage:
Low Level Voltage:
High Level Current:
Low Level Current:
Receivers:
Difftial I/P threshold:
Hysteresis:
Input Impedance:
60.00mHz
SN75174
3.7V typical at 33mA source
1.1V typical at 33mA source
-60mA max.
60mA max.
SN75175.
200mV max.
50mVolt typical.
>12K Ohm without terminators.
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