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RS-232 operation
9XTend-PKG-R RS-232/485 RF Modem User Guide
15
The following table shows the RS-232 Signals and their implementations on the XTend RF Modem (Low-asserted
signals are distinguished by horizontal line over pin name).
Wiring diagrams
The following diagram shows the RS-232 DTE Device (male DB-9 connector) wired to a DCE RF modem (female DB-9).
DB-9 Pin
RS-232
Name
Pin Reference
Name
Description
Implementation
1
DCD
GPO2
Data-Carrier-Detect
Connected to DSR (pin6)
2
RXD
DO
Received Data
Serial data exiting the RF modem (to host)
3
TXD
DI
Transmitted Data
Serial data entering into the RF modem (from host)
4
DTR
GPI2
Data-Terminal-Ready
Can enable Power-Down on the RF modemy
5
GND
-
Ground Signal
Ground
6
DSR
GPO2
Data-Set-Ready
Connected to DCD (pin1)
7
RTS
/ CMD GPI1
Request-to-Send /
Command Mode
Provides
RTS
flow control or enables Command Mode
8
CTS
GPO1
Clear-to-Send
Provides
CTS
flow control
9
RI
-
Ring Indicator
Optional power input that is connected internally to the
positive lead of the front power connector
1. The ‘Pin Reference Name’ provides an associative tag that references commands used to define pin behaviors. GPI stands for "General
Purpose Input" and GPO stands for "General Purpose Output". As an example, the CD command is used to define the behavior of GPO2 (DB-9
pin number 1). The ‘Pin Reference Name’ is the name used when referring to XTend commands and parameters.