AI-Tek Instruments TACHTROL 3, Инструкция по эксплуатации, Страница: 7 / 30

Once you have selected a function for and determined the behavior of each output, you set up
the instrument by entering twelve 4 1/2 digit, signed numbers (called constants) on the thumbwheel
and pushbutton switches on the control panel located behind the Door. These constants are held in
the TACHTROL
®
3 tachometer’s electrically alterable, read only memory (EAROM) and can be indi-
vidually displayed and altered by a method similar to the setting of a digital watch. You then mount
the instrument, install the speed sensor(s), connect the sensor(s) and the power wiring, and you are
ready to operate. The following chart describes the purpose of each constant (C
1
thru C
12
) and lists
the standard constants which are preset in the instrument.
Constant Purpose Std. Constants
C
1
and C
2
scale (normalize) the input signal 1.000
frequency from channel A.
C
3
and C
4
scale (normalize) the input signal 1.000
frequency from channel B.
C
5
provides an additional method of scaling. When C
5
is 1.000
set to standard constant. Display shows the computed
function of channel A or channel B. However, C
5
can
be altered to convert one engineering unit to another
for Display purposes only. For example, C
5
can be used
to configure the instrument so that RPM is being com-
puted and FPS Is being displayed. This Is Illustrated by the
following equation.
A
rpm
x C
5
= D
fpm
where A = scaled Input signal frequency
D = display value
C
6
sets the Analog Output Zero Scale by determining at 0.000
which value of the analog function (C
11
) the analog
output delivers 0 or 4mA to the load.
C
7
sets the Analog Output Full Scale by determining at 2000
which value of the analog function (C
11
) the analog
output delivers 20mA to the load.
Note: You can make the Zero Scale larger than the Full Scale to compute Inverse functions.
C
8
determines at which value of the selected function (C
11
) 1000
setpoint one relay K1 changes to the alarm state.
C
9
determines at which value of the selected function (C
11
) 1000
setpoint two relay K2 changes to the alarm state.
C
10
determines the independent reset point for both relays. 0505
(Hysteresis The Hysteresis (dead band) may be specified in 1%
Constant) steps from 00 to 99% of the setpoint value.
C
10
SP2 SP1
3