Vaisala RVP900

Chapter 7 __________________________________________________ Host Computer Commands
VAISALA______________________________________________________________________ 257
CHAPTER 7
HOST COMPUTER COMMANDS
This chapter describes the digital commands that the host computer must
use to set up and control the RVP900 processor for recording data. Each
command is described in detailed in a separate section of this chapter. Note
that a command mnemonic, or shorthand reference name, is given in each
section heading. These names are frequently used to refer to particular
commands.
The write-up for each command includes a description of what the
command does and a pictorial layout of the bits in the 16-bit command
word. Commands consist of an initial command word containing an
opcode in the low five bits. If additional arguments are required, they are
listed as "Input 1", "Input 2", etc. Finally, if the command produces output,
those words are listed as "Output 1", "Output 2", etc. Often each word is
broken down into several independent fields, each consisting of one or
more bits. In such cases, the pictorial layouts show the placement of the bit
fields within the word, and each field is described individually. All data
transferred to or from the RVP900 are in the form of 16-bit words.
Before attempting to program the RVP900, it is a good idea to at least skim
through the descriptions of every command. The instruction set has been
designed to be as concise and orthogonal as possible. User programs
should always execute the IOTEST command on power-up to ensure that
the interface connections are all intact. The diagnostic result registers from
GPARM should also be checked initially to verify that the RVP900 passed
all internal checks. Since all internal RVP900 tables and parameters are set
to reasonable values on power-up, it is conceivable that PROC commands
could be issued immediately to acquire and process radar data. More
realistically, however, the default information is first modified to meet the
users needs.
To set up for data acquisition and processing the following sequence of
commands might be executed. Trigger and pulse width are first established
using the SETPWF commands. Range bin placement and processor