Vaisala RVP10, Быстрый справочник по оборудованию

Страница: 17 / 34

Table 8 Socket protocol commands
Command Example
Read
(
READ )
Example: READ|100| means: Read 100 bytes from the RVP10.
Since the RVP10 interface is a 16-bit word interface, these read sizes
should always be even.
This command returns a
Ack| followed by 100 bytes of binary data, or
with a Nak| , meaning there can be no partial reads.
Write
(
WRIT )
Example:
WRIT|<data>
, where
<data>
is some binary data.
This data is written to RVP10. The data size should be even.
Read Status
(
STAT )
Example: STAT| reads the status bits back from the RVP10. This is a 1-bit
value, set to 1 if RVP10 has data available in its output buffer.
The command returns Ack|0 , Ack|1 , or Nak .
This is equivalent to the dspr_status() call in the dsp library.
Set Information
(
INFO )
Example:
INFO|
ByteOrder=LittleEndian,WillCompress=1,Version=10.0
.
This command can be used to inform RVP10SRV
DspExport
about the
host computer. Available options are:
•
ByteOrder —Informs DspExport of the byte order of the host
computer. This is needed because all the data read or written to/from
the RVP10 is in 16-bit words. If the host computer has a different byte
order from the RVP10, DspExport byte swaps the data.
• WillCompress —Informs DspExport to use compression or not.
Compression is only used if both sides agree to use it. The host
computer should only set this to 1 if it received a
CanCompress of 1 on
initial connection. The data from normal READ commands is
compressed.
If the data is compressed, it replies with the acknowledge compressed
string of
AkC
.
The compression program is the zlib compress and uncompress. The
uncompress function requires that the caller know the expected
uncompressed size. This is true for RVP10 reads, because the reader
always specifies the read size.
• Version —Sends the IRIS version.
Read Data Available
(
RDAV )
Example:
RDAV|100|2|
means read up to 100 bytes of data from the
RVP10SRV in individual DMA transfers of 2 bytes each.
Before each read, the status is checked to see if there is more data
available. If not, the read stops, and the number of bytes read is returned.
This is merely a performance enhancing command, since the same
feature is available by using the
READ
and
STAT
commands.
Chapter 3 – Hardware description
RESTRICTED 17