Table of Contents
Advertisement
Technical Description
The Sealevel Systems ULTRA 530.LPCI provides a PCI interface adapter with an
additional asynchronous serial port providing a versatile interface, field selectable as
RS-232 for modems, printers and plotters, as well as RS-422/485/530 for industrial
automation and control applications.
The ULTRA 530.LPCI utilizes the 16850 UART. This chip features programmable
baud rates, data format, interrupt control and a 128-byte input and output FIFO. The
ULTRA 530.LPCI also supports the Oxford Semiconductor 16C950. This chip
features the same FIFO, and automatic RS-485 driver enable capabilities as the
16C850 and the ability to receive a clock for isochronous communications.
Isochronous Communications
Webster's New Collegiate Dictionary defines synchronous as "recurring or operating
at exactly the same period." The majority of the serial buses in use today operate
asynchronously, that is, "not synchronous" or more literally, not clocked. The same
dictionary defines isochronous as "uniform in time; having equal duration; and
recurring at regular intervals." In this implementation of serial communications,
isochronous is defined as asynchronous framing (i.e. start, stop and parity bits) with
the addition of a clock signal. This scheme allows for much higher data rates and the
use of digital lines (i.e. ISDN, T1) where a clock is supplied for data multiplexing.
Connector Pin Assignments
RS-232 Signals (DB25 Male)
Note: These assignments meet EIA/TIA/ANSI-232E DTE
Technical Note: Please terminate any control signals that are not going to be used.
The most common way to do this is connect RTS to CTS and RI. Also, connect
DCD to DTR and DSR. Terminating these pins, if not used, will help insure you get
the best performance from your adapter.
© Sealevel Systems, Inc.
Signal
GND
Ground
RD
Receive Data
CTS
Clear To Send
DSR
Data Set Ready
TXC
Transmit Clock
RXC
Receive Clock
DCD
Data Carrier. Detect
RI
Ring Indicator
TD
Transmit Data
RTS
Request to Send
TSET
Transmit Signal Element Timing
DTR
Data Terminal Ready
Name
- 12 -
Pin #
Mode
7
3
Input
5
Input
6
Input
15
Input
17
Input
8
Input
22
Input
2
Output
4
Output
24
Output
20
Output
ULTRA 530.LPCI User Manual
Advertisement
Table of Contents
