Message polling – Vaisala FD12P User Manual

Page 69

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Chapter 4 _________________________________________________________________ Operation

VAISALA ________________________________________________________________________ 69

Message Polling

In the polled (CLOSEd) mode, the FD12P sends a data message when
the host computer transmits a polling command. The message polling
mode is selected by the following command:

AMES Message_number Message_interval

↵↵

where

Message_number

- The valid range is 0 ... 7, refer to section Message Types on

page 63.

- Selects the corresponding message as the default polled

message. Any negative message number is converted to 0.

Message_interval

- Negative or zero interval is used to disable the automatic

sending. This is used when messages are polled.

For example, AMES 0 0

↵ selects message 0, and cancels the

automatic sending.

The polling command format is the following:

<ENQ> FD <SP> id <SP> message_number <CR>

where
<ENQ>

=

ASCII character 05 hex

<SP>

=

ASCII character 20 hex (space)

id

=

Selected in the configuration

message_
number

=

Optional

If only one FD12P unit in on the line and no id is set, the command
format is the following:

<ENQ> FD <CR>

When the FD12P unit number two (id = 2) is polled for message
number 3, the command format is the following:

<ENQ> FD

<SP> 2 <SP> 3 <CR>

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