2 using the rs 232c serial bus, 4800 baud, Even parity – Vaisala HMP228 User Manual
Page 22: 7 data bits, 1 stop bit, Full duplex
HMP228
Operating Manual
M210282en-A
16
3.2
Using the RS 232C serial bus
Rx GND Tx
Rx
GND
Tx
Nc
24V
Sensor connections
Current loop or
RS485 module
Ch1 Ch2
+ -
nc
Tx
GND
Rx
-
- +
+
X17
X6
Figure 3.2.1
Serial bus connections
To connect a PC to the HMP228 transmitters via the RS 232C serial bus, one
of the following cables is required. The type of cable depends on the terminal
and the connector type.
2
5
3
3
7
2
3
7
2
TX
GND
RX
TX
GND
RX
TX
GND
RX
HMP228
D9S
D25S
D25P
PC
TXD
RXD
TXD
TXD
RXD
RXD
4
6
7
8
5
6
8
20
TERMINAL
Figure 3.2.2
Connection of cables
When the serial bus has been connected between the PC and the transmitter,
the PC is switched on. When using a PC, a terminal emulation programme
(e.g. Procomm Plus, Datastorm or Windows terminal) is started.
The factory settings for data transfer are:
•
4800 baud
•
even parity
•
7 data bits
•
1 stop bit
•
full duplex