RS232 Port
PSI BOX Reference
CHAPTER 5
THE RS232
SERIAL PORT.
Introduction.
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This chapter describes the RS232 port on the PSI BOX.
The RS232 serial port connector pin outs, the function of the
DIP switches and LEDs, how to set the baud rate, parity and
RS232 handshake options are explained in detail. Details of how
to connect the PSI BOX to both an IBM PC and a modem are
included.
Summary.
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The RS232 port signals are the industry standard +/- 12
Volt level. The serial port is an IBM PC serial compatible port.
The connector has the same pin outs as the IBM PC serial port
COM1: etc. A 25 way male D connector, with screw locks for
secure connections, is used.
The serial port is bi-directional. The baud rate and parity
options are selectable from the front panel. Baud rates between
75 to 19200 baud are available. Parity may be off or on, even or
odd. The may be either 7 or 8 data bits per word. A front panel
LED flashes whenever the RS232 port sends a byte. A front
panel LED flashes whenever the RS232 port receives a byte.
The RS232 port lines are implemented with the PSI BOX
as the Data Terminal Equipment, DTE. The PSI BOX can be
used for asynchronous communications only. It is not for
synchronous communications.
Chapter 5
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