RayTek LineScanner MP150, Руководство по протоколу

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Transmission of Temperature Lines
12
Rev. B4 Aug 2019
MP150 Protocol
4 Transmission of Temperature Lines
A scanned line is composed of a count of temp erature points which will be termed a ‘pixel.’ Depending
on the point mode the data transmission can have lines of 64, 128, 256, 512 or 1024 pixels and, depending
on the data mode, a pixel can be represented with 1 or 2 bytes.
The data transmission depends on previous commands which define options and parameters. It is
defined by:
•
The Data Mode (DM): it defines the type of information that will be sent as a “pixel”, see section 4.2
•
The Point Mode (PM): it defines the count of pixel within the 90° field of view, see section 4.3
•
The Line Mode (LM): it defines the frame around the pixel data and some data that can be appended
onto the line, see section
4.4
•
The Receive Mode (RM): it switches between continuous transmission (“Burst Mode”) and the
transmission of requested snapshots (“Host Mode”).
•
The Line Count (LC): defines the count of lines per snapshot.
The composition of the response is described in section
4.4 . The parameters/options that change this
composition are described in the following subsections.
4.1 Starting and Stopping the Data Transmission
The request of temperature lines by the PC is always initiated by transmitting STX. The scanner will
respond to the request with a SYN.
As soon as the data is processed into temperatures, transmission will begin. (The transmission may be
delayed several seconds if the averaging value is high.)
If the scanner receives an ESC, its data transmitting is halted,
and the scanner’s internal data buffer is
cleared. Then, the scanner will be ready for new commands, parameters and data requests.
As it takes a short amount of time for the scanner to complete the buffer clearing process, there may be
some data streaming from the scanner up to half a second after sending ESC.
4.1.1 The Receive Mode (
RM
): Burst or Snapshot (Host)
There are two modes to handle the initiation of data transmission:
•
Host Mode (
RMH
) : Requesting of snapshots with a predefined length (Line Count)
•
Burst Mode (
RMB
) : Requesting a continuous stream of lines
Both are started with sending a
STX
to the scanner. The scanner will respond to the request with a
SYN
.
Set to host mode an additional trigger condition (set with the command Zone Mode ZM) can be given
to synchronise the transmissions start with an event. Once started the transmission will stop after the
count of lines which was defined with the LC command or by sending an ESC character. Each new
snapshot needs a STX character to be sent.
This host mode was implemented with the background of a very slow data channel (the transmission
rate can be lower than the data generation rate). The lines that cannot be transmitted will be buffered
and a new snapshot cannot be initiated until the complete snapshot will have been transmitted.
Set to burst mode the transmission will start without any condition after having transmitted the
STX
character. Once started the transmission will stop with sending an
ESC
character.