Polled Mode - Vaisala LT31 User Manual

User's Guide ______________________________________________________________________
182 _________________________________________________________________ M210667EN-C
The automatic message interval is selected with the command SET
MESSAGE INTERVAL. The message interval is given in seconds. An
interval of zero which ignores the automatic sending, is used when the
messages are polled. The command format is as follows:
SET MESSAGE INTERVAL Message_interval
The following command selects the message to be sent once a minute:
SET MESSAGE INTERVAL 60
The following command cancels the automatic sending:
SET MESSAGE INTERVAL 0

Polled Mode

In the polled mode the LT31 system sends a data message when the host
computer transmits a polling command. The automatic message sending
mode is disabled by setting the message interval to zero with the
following command:
SET MESSAGE INTERVAL 0
The polling command format is as follows:
%LT<id><message_number>-
where
= The ASCII character number 5 (CTRL + E)
%
id = The identifier selected in configuration; if replaced
by blank space all LT31 systems on the line will
respond
message = Optional message identifier (two characters); if the
number message number is omitted, the sensor answers with
the default message selected with the SET
MESSAGE TYPE command
= CR (ASCII 13)
-
Examples of polling commands:
= If only one LT unit is on the line (no ID is
%LT-
necessary)
= The LT31 unit A (ID = A) is polled for message
%LTA03-
number 03 (status message). This is used when
several devices are on the same line.