User's Manual Part 2
Host Computer Commands
RVP8 User’s Manual
May 2003
6–34
command) corresponds exactly to the instant at which data at range zero are sampled by the
RVP8. Note that the output rate can also be interpreted as a new bit coming every 1/48 km. In
some cases this is a more useful view.
As an example, suppose we wish to make the TGEN0 output be a 0.42 microsecond pretrigger
pulse, with a rising edge exactly five microseconds prior to range zero. This would be done by
setting bit 0 in input words 988, 989, and 990 following the TRIGWF command, and leaving all
other bit 0’s clear. Further, if TGEN1 was to be a 0.14 microsecond marker strobe at 20km, we
would simply set bit 1 of input word 1984.
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
| | | | | | | | | | | | | | | | |
| |PW3|PW2|PW1|PW0| | 0 1 1 0 1 | Command
|_______________|___|___|___|___|___________|___________________|
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
| | | | | | | | | | | | | | | | |
| H | | Transition Point of POLAR0 Control Line | Input 1
|___|_______________|___________________________________________|
H This bit defines the sense of the control line when horizontal polarization is se-
lected.
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
| | | | | | | | | | | | | | | | |
| | Bits for –142.22 usec | Input 2
|_______________________________________|___|___|___|___|___|___|
.
.
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
| | | | | | | | | | | | | | | | |
| | Bits for zero range | Input 1025
|_______________________________________|___|___|___|___|___|___|
.
.
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
| | | | | | | | | | | | | | | | |
| | Bits for +142.08 usec | Input 2049
|_______________________________________|___|___|___|___|___|___|
6.13 Define Pulse Width Control Bits and PRT Limits
(PWINFO)
The RVP8 is equipped to control the radar transmitter’s pulse width and corresponding receiver
bandwidth. There are four pulse/bandwidth codes, numbered simply 0 through 3. The
association between codes and pulse widths is completely determined by the needs and
capabilities of the particular radar on hand. In some cases, the zero code might represent 0.25
microsecond pulse width, and in other cases it may represent 2.0 microseconds. Likewise, some
radars may use all four codes, whereas others have fewer options from which to choose. The
PWINFO command defines what happens for each of the four possible codes, but does not
actually select which code is being used. The later function is performed by SETPWF.
The RVP8 drives four TTL output lines (PWBW0 – 3) which are intended to control the radar
pulse/bandwidth hardware. Typically this control is via relays or solid-state switches in the
transmitter and receiver. The user decides what state the four lines assume for each pulse width