User's Guide ______________________________________________________________________
38 __________________________________________________________________ M210482EN-B
the same commands, operations, and messages operate through any of
the lines, and the following description applies to both of them.
The factory default setting is 8 data bits, No parity, 1 Stop bit, and for
baseband lines, 9600 maint, 19200 data. The bit rate can be selected
from the user menu.
Both use the 7-bit USASCII character format. Both the UPPER and
lower letter cases can be used.
The standard operation of the serial lines requires no handshake
signals.
A communication port, in other words the serial line, has the
following two internal states (Figure 15 on page 39):
- CLOSED: This is the measurement data message transmitting state.
In this state, messages are transmitted as a response to a polling
input string or automatically at predetermined intervals, depending
on the corresponding settings (message transmission). User
commands are not accepted, except for the
open
command, which
turns the line into the OPEN state.
- OPEN: This is the user dialog state. In this state, the user
commands are responded to and command input is echoed. A
command prompt
CEILO >
is displayed to indicate that CL31 is
ready for command input from the user. The commands are
executed by pressing ENTER, for example,
OPEN 1 <enter>
. No
automatic transmission of the measurement data message is
executed in the open state. The port reverts to the closed state with
the
close
command. An automatic, 2-minute time-out after the last
character input is applied. A 2 to 30-minute time-out may be set
with the
set port_time_out
command.
NOTE
Only one of the ports can be open for commands at a time. Only one
of the ports transmits measurement messages at a time. Additionally,
in the RS-485 mode, a unit ID must be given with the
open
c
ommand.
