SECTION SEVEN
–
PTP COMMUNICATION PROTOCOL
IDRONAUT
–
Brugherio (MB)
OCEAN SEVEN 304
Plus
CTD
12-2015
50
7.
PTP COMMUNICATION PROTOCOL
The OCEAN SEVEN 304
Plus
CTD is operated according to a series of rules and message formats
commonly indicated with the term ”communication protocol”. The OCEAN SEVEN 304
Plus
supports
a very simple communication protocol, with function selections (incoming data) and sensor readings
(
outgoing data) assembled in ”messages” whose generic structure is the following
:
ID[ <param list>] <LF> or <CR>
“ID” is a two
-character identification for the message;
for example “PT” stands for single
CTD real-
time acquisition. The message identification is optionally followed by a space and a list of parameters,
whose number and format strictly depend on the type of message.
Each incoming message must end with an
<LF>
, that is the ASCII character line-feed (0x0A
hexadecimal, 10 decimal). Vice versa, the Line Feed character on a PC keyboard can be obtained by
pressing the
<CTRL-J>
(press and hold the
<CTRL>
key, press and release the
”J”
key, release the
<CTRL>
key). The CTD operates in
”slave” mode, meaning that it does nothing but waits for user
commands to be received. When a complete message is received, its ID field is searched for in a
lookup table and, if a match is found, the system dispatches the received message to the appropriate
handler. The message handler is responsible for verifying each parameter and carrying out the desired
action; the action usually consists in assembling and sending back another message.
The document
“
OCEAN SEVEN 3xx Data Transmission Protocol
”
describes in detail the communication
protocol. It can be found in the download area of the IDRONAUT web site.
Содержание Ocean Seven 304Plus
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