Vaisala HMP240 - Manual (Page 23)

HMP240 series
M210300en User's Guide
21
2
5
3
3
7
2
3
7
2
TX
GND
RX
TX
GND
RX
TX
GND
RX
HMP 243
D9S
D25S
D25P
PC
TXD
RXD
TXD
TXD
RXD
RXD
4
6
7
8
5
6
8
20
TERMINAL
Figure 4.5 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
NOTE
When the serial bus settings are changed, the transmit-
ter has to be reset before the new settings become ef-
fective.
The processor does not allow the following combinations:
• no parity, 7 data bits, 1 stop bit: if this combination is given the
HMP240 programme will change the number of stop bits to 2
• even or odd parity, 8 data bits, 2 stop bits: if this combination is given
the programme changes the number of stop bits to 1
Refer to the manuals of the PC and the terminal emulation programme when
giving serial settings.
The RS 232C screw terminal cannot be used if an RS 485/422 serial module
or a current loop module is used. See Appendices 2 and 3 on how to install
and operate these modules.