Xylem H-4191 - Manual (Page 6)

1-4 Operation
H-4191
1.3 Making Connections
Connect the RS-232 port of the H-4191 to the serial port of your personal computer or other host
device with a standard 9-pin RS-232 cable (provided). The H-4191 has a female connector and is
a DCE (modem) device. The cable has 9-pin RS-232 connectors which can be plugged directly
into a PC serial port without the use of gender or null-modem adapters. Program your host device
for 9600 baud, 8-bit, no parity, full-duplex communication The host device must assert either
CTS or DSR to awaken the H-4191 from it’s low power sleep mode.
RS-232 Connector
Pin Name Direction Description Function
1 nc not used
2 TxD Output Transmit Data Transmit data to host device
3 RxD Input Receive Data Receive data from host device
4 DSR Input Data Set Ready Awakens the H-4191 when asserted.
5 GND Ground Ground
6 nc not used
7 CTS Input Clear To Send Awakens the H-4191 when asserted.
Controls TxD if RTS/CTS flow
control is on.
8 RTS Output Request To Send Asserted when awake and output
buffer is not full
9 nc not used
The H-4191 has a 4-position
terminal strip for making
connections to the SDI-12
bus. The H-4191 is powered
from the +12V power
terminal.