- Contents
- Focus_
- Overview
-
Satellite_POCSAG_description
-
Batch_Control_frame
- Decode_frame
- Focus
This page relates to the PPEViewer,
Satellite POCSAG tab.
- Overview
The Satellite Decoder window decodes the POCSAG Satellite data stream from the satellite receiver.
This page explains the decoder window.
- Satelite POCSAG
description
This version
includes the serial input, TCP input as well as the file input. The
tab only displays information, all the configuration is now in the
System Config tab.
This tab is now
resizable. It also remembers the form size when the application
closes. It can be maximised as well.
Numeric encoding now has a filter on it such
that if a numeric is detected the output will show the numeric
interpretation then the alpha interpretation. The numeric
interpretation is preceded with "<n>" and the alpha with "<a>".
Batch Control frame
This
display now indicates the header batch information i.e. F1 or F2 and
Baud rate of the current batch. There is also a display of the
current buffer size of the input data stream. This should normally
be 0 though it could momentarily increase due to processing delays.
If the buffer size exceeds 20000 then data will be lost.
Decode frame
This is the decoded POCSAG data stream
including header information pertinent to the transmission. Each
transmission is headed with information such as Frequency and
Baud Rate as well.
The format of the display is configured with
the help of check boxes in the System Config tab, Satellite
POCSAG/Output Config frame. Simply check the boxes to add header
information in front of each decoded message. Each message in the
output stream starts with a CR/LF. There is also the Raw POCSAG
check box which converts the output to messages embedded in the
POCSAG frame structure.
This
same information is logged to the
".\logs\PPE__out.log"
This is hard coded in the current version to this location.
Backups are sent to the ".\backup" directory and have an added
file name extension of the current date and time. e.g.
"2007-9-20-13-23-45_PPE_out.log".
The display can be cleared at any time by
hitting the Clear button in the display.
The Clear display (top right) command is in the main display. There
are also scroll bars in
both directions. This is a bit limited in usefulness as the display
is refreshed on each data entry. Later versions will provide pause
control on the data stream. The output is shown below with time,
frequency and baud rate headers..
Improved Satellite Asynchronous
Decoder
The Viewer now has been
changed to operate with the new MTEL PPE Encoder for satellite
transmission. The Asynchronous data stream has no EOT character
sequence therefore a 300millisecond data absence timer was added
to test for the end of the data stream. This will also help the
decoder during staellite fades.
The display has been
changed to make the batches more distinguishable. It has the
same format as the older decoders so the log file can be processed by
existing filters.
The previous MC01 device
had NULL markers at the end of transmission, which allowed the
previous version to operate correctly. The new PPE ENcoder also
has end of transmission characters however the 300mSecond timer
is a better termination in case of corruption.
The window below shows
the decode and the Batch Control label indicating the data
stream has expired.
The state machine has
been dramatically increased in speed since the bit stuffing for
the MC01 is no longer required. The data runs pure POCSAG decode
in ASCII format with fixed 32 bit boundaries.
