4-6
Model 3786 Ultrafine Water-based Condensation Particle Counter
The SBC is setup to provide the PC/104 Serial port to be a terminal
server. A terminal or computer running terminal emulation
software can access the SBC through this port. A Null Modem
(crossover) cable is needed to connect a computer to this port. The
default serial settings for the PC/104 terminal server are:
Baud Rate .................... 9600
Bits/Character................... 8
Stop bits ............................ 1
Parity ........................... None
A login prompt is provided. The user name and password for the
default configuration of the SBC are:
User Name:
root
Password: emac_inc
The SBC Ethernet port (eth0) is configured to gather an IP address
from an external DHCP server. For the SBC to actually acquire an
IP address it must be connected to a network with an active DHCP
server BEFORE powering up the UWCPC. The connection to the
Ethernet port must be made with a shielded twisted pair 10-BaseT
network cable. The Ethernet configuration may be changed to
provide a static IP address using the start up configuration routine
provided.
The terminal emulation program “minicom” has been configured to
use one of serial ports (/dev/ttyS1) to communicate with the
UWCPC through an internal connection. This program may be used
to test operation with the UWCPC and even to capture data. It
should be noted that the SBC is setup with a “read-only” file
system. This ensures that when the UWCPC is turned off and the
SBC is brought down “hard”, the SBC will boot cleanly on the next
power up. This also means that for data to be saved to the SBC it
must be either written to the “/var” directory which is mounted
read-write in RAM, or the file system must be mounted read-write
during the moments when data is to be written.
A demonstration program has been included named “WCPCLog”
and is located in the directory /home/WCPC. The program written
in “C” initiates a SM,2,60 command, captures the data (D) records
returned by the UWCPC, timestamps them, stores them, and
creates a new data file each day. A link to the /home/WCPC
