Xl™ series – Xylem XL Series H-522 - Plus User Manual
Page 64
6-6 Serial Port Options
XL™ Series
Figure 2-5 RS-232 Connector
6.3 Serial Port Hardware Description
The three RS-232 ports are used to connect to a PC, GOES Transmitter, modem, remote display,
or other serial equipment for standard serial communications. These ports are configured as a
DTE type of device. This means they will plug directly into a modem (a DCE type device), but
will require a NULL modem adaptor if connected to a PC (a DTE type device). The NULL
modem cable crosses the communication lines allowing two similar devices to communicate.
Figure 2-5 shows the pin out for all three ports.
SERIAL PORT PIN-OUT
PIN
DIRECTION
NAME
1
Input
Data Carrier Detect
(DCD)
2
Input
Receive Data
(RD)
3
Output
Transmit Data
(TD)
4
Output
Data Terminal Ready
(DTR)
5
Ground
(GND)
6
Input
Data Set Ready
(DSR)
7
Output
Request To Send
(RTS)
8
Input
Clear To Send
(CTS)
9
Input
Ring Indicator
(RI)
6.4 Serial Port Functions