micro-trak MT-3405F II, Справочное руководство

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Appendix G - Using the MT-3405 II with VRA
The MT-3405F™ II has a 9-pin serial connector on the
back panel which allows it to be connected to any “GPS /
Mapping Controller”.
A GPS/Mapping system typically consists of special
hardware that runs on a laptop/PDA, or dedicated mapping
controller. The MT-3405F™ II may be connected to any
such device that supports Micro-Trak products.
This allows for the following mapping activities:
“AS APPLIED” MAPPING
In this case the GPS/Mapping Controller just collects data.
In either MAN or AUTO operating modes, the console
simply reports its current application rate.
VARIABLE RATE APPLICATION
In order to accept VRA commands, the console must be
operating in ‘AUTO’.
While in ‘AUTO’, the GPS/Mapping computer is in control of
the application rate, and consequently the console’s adjust
rate buttons (+ and -) are disabled.
When outside of the prescribed mapping area, the GPS/
MAPPING computer puts the MT-3405F™ II in “Hold” (stops
spraying) by simply sending a target rate of zero.
MANUAL OVERRIDE OF VRA
There may be times when the operator needs to
apply more or less that the prescribed rate. In such
a case, pressing ‘MAN’ allows the operator to make
adjustments using the + and - buttons. To resume the
prescribed rate, simply exit the manual override by
pressing the AUTO button.
NOTE: While in MAN override, the console will not
miss any new rate commands sent by the GPS/
Mapping Controller. They are simply ignored until
the user toggles back to AUTO, at which point the
most recent prescribed rate is resumed.
VRA Testing Procedures:
CABLE CONNECTION
Use a standard pin-for-pin (not “null-modem”) serial
communications cable to connect the Micro-Trak console to
the GPS/Mapping controller. One end of the cable should
be a DB9 male and the other end a DB9 female.
NOTE: Only 3 wires are used (Tx, Rx and Gnd: Pins 2, 3 & 5).
COMMUNICATIONS SETTINGS
The Micro-Trak console uses the following serial settings:
9600 baud, 8,N,1 (8 data bits, no parity, 1 stop bit).
NOTE: These numbers are in the software NOT the Micro-
Trak Console.
FUNCTIONALITY TEST
You can verify the connection and functionality by using
the standard “HyperTerminal” communications program,
which can be found on any computer running MS-Windows.
Connect a computer (PC, laptop) to the Micro-Trak console,
and configure HyperTerminal (‘Port Settings’ tab) as follows:
•
Select a known working COM port on your computer
• Select the communication settings as listed above:
IMPORTANT: ‘Flow Control’ must be set to none.
The following tests assume the Micro-Trak console is power
up, and ‘AUTO’ is selected ( DOES NOT require speed or flow
signal).
1. Put console into HOLD, by sending a target rate of zero.
Type the following, a signal character at a time: S,0,
(capital S; comma; then ZERO and a trailing comma).
The console goes into HOLD immediately after the last
comma.
2. Send a new target rate.
Send a target rate of 12.3 by typing: S,123,
Once the trailing comma is sent, the console
immediately changes to the new target rate of 12.3.
3. Verify the new rate
Retrieve current rate status by typing one character: R
The console immediately responds with a ‘D’ followed
by a number of comma-separated fields (datalist):
• The 1st data field (D,123,) is the current target rate [12.3].
• The 2nd data field (D,123,###, is the actual rate.