Owner manual

Technical Description
Sealevel Systems PC-COMM+232 Page 6
Technical Description
The PC-COMM+232 provides two RS-232 serial ports utilizing XR16C850
UARTs (Universal Asynchronous Receiver Transmitter). The XR16C850 is
compatible with the 16550 UART. The ‘850 is an enhanced UART with 128
byte FIFOs, automatic hardware/software flow control and the ability to handle
much higher data rates than standard UARTs.
Connector Pin Assignments for RS-232 (DB-9 Male)
Signal Name DB-9* Mode
GND Ground 5
TD Transmit Data 3 Output
RTS Request To Send 7 Output
DTR Data Terminal Ready 4 Output
RD Receive Data 2 Input
CTS Clear To Send 8 Input
DSR Data Set Ready 6 Input
CD Carrier Detect 1 Input
RI Ring Indicator 9 Input
* Note: These assignments meet EIA/TIA/ANSI-574 DTE for DB-9 type
connectors.
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.