User's Guide _______________________________________________________________________
32 ___________________________________________________________________ M211060EN-H
For temporary use of the serial interface (for example, calibration), you
can use the optional USB cable (Vaisala order code: 219690). Before you
can use the USB cable, you must install the provided USB driver on your
PC: see Installing the Driver for the USB Cable on page 32.
NOTE
The Vaisala USB cable is not designed for permanent installations.
When using the USB cable, no separate power unit is needed. The probe
is powered through the USB port.
For permanent interfacing to a host system, use a shielded cable with a
threaded connector. For a list of available cables,see Options and
Accessories on page 74.
The probe does not echo typed characters back to the terminal screen. To
see the commands you type, you need to enable the "local echo" setting
in your terminal program.
A new command cannot be received while the probe is sending data out.
Wait until the instrument has completed its response before entering the
next command.
Table 8
Default Serial Communication Settings
Parameter
Value
Baud rate
19200
Parity
None
Data bits
8
Stop bits
1
Flow control
None
You can change the serial settings and operate in RUN, STOP, POLL
and MODBUS modes.
After power-up the probe (in STOP mode) outputs the software version
and the command prompt.
- In RUN mode, a measurement output starts immediately after power-
up.
- In POLL mode, the probe does not output anything after power-up. It
must be accessed with an addressed command.
- In MODBUS mode, the probe does not output anything after power-
up: serial line commands are not in use and the probe must be used
with the Modbus protocol. For instructions on returning to serial
mode, see Accessing Serial Line Command Interface (RS-485 Mode)
from Analog or Modbus Mode on page 36.
For a description of the modes and the SMODE command that is used to
change the mode, see section Set Serial Interface Mode on page 44.
