User's Manual Part 2

Host Computer Commands
RVP8 User’s Manual
May 2003
6–13
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
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| Starting Range in km (Max 992km) of 32km Sampling Interval | Input 1
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15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
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| Internal Trigger Rate (6Mhz/N) to use During Noise Sampling | Input 2
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6.7 Initiate Processing (PROC)
The PROC command controls the actual processing and output of radar data. The operating
modes and types of data available from the RVP8 are described in detail in Chapter 1. That
section also describes the proper use and application of the RVP8 to different radar
environments.
PROC is a single-word command that specifies the type of processing to be performed, and the
type of output to be generated. The two mode bits in the command word select either
 Synchronous mode — The processor acquires, processes, and outputs one ray in response to
each PROC command. Processing is begun only after each command is actually received.
 Free running mode — A single PROC command is issued and rays are continually output as
fast as they can be produced and consumed. This continues until any other command is
written, e.g., a NOP could be used to terminate the free running mode with no other
consequences.
 Time Series mode — Always produced in a synchronous manner, this mode require a new
PROC command to initiate each new set of samples. Data are output as 8-bit time series,
16-bit time series, or 16-bit power spectra.
Optional Dual-PRF velocity unfolding is chosen by command bits eight and nine. For Doppler
data either a 2:3, 3:4, or 4:5 PRF unfolding ratio may be selected. The RVP8 carries out all of
the unfolding steps internally, so that mean velocity is now output with respect to the larger
unambiguous interval. There is no additional velocity processing needed by the user, except of
course, to change the velocity scale on any displays being generated. Furthermore, spectral
widths are scaled consistently with respect to the higher PRF, and require no user modification
before being plotted.
When unfolding is selected, the internal trigger generator automatically switches rates on
alternate rays. The switch over occurs immediately after the last pulse of the current ray has
been acquired; thus overlapping the internal post-processing and output time, with transmitter
stabilization and data acquisition at the new rate.
Output data are selected by the upper six bits of the PROC command. Packed archive output is
selected by setting the ARC bit. Individual byte or word display output is selected by setting any
or all of the Z, T, V, W, Zdr, and KDP command word bits. When more than one of these bits is
set, the output array consists of all of the bins for the leftmost selected parameter, followed by all
of the bins for the next selected parameter, etc. Bits selected in XARG #1 behave the same way,
except that the output order is right-to-left. Both archive and display formats can be selected