ANALOG INPUT SECTION 10
Page 10-5 RPC-320
The output voltage from the tem perature sensor is
doubled by jumpering H1[5-7]. While this does not
change the range the unit operates at, it does change
increase temperature measurement sensitivity.
Data logging on a timer tick
Some applications require that data is read at fixed
intervals. The ONTICK construct is used to take data in
intervals from 0.01 to 327 seconds. The example below
takes 1 sample per second until 100 samples have been
obtained.
10 DIM A(100)
20 ONTICK 1,500
30 REM THE REST OF YOUR PROGRAM
40 REM CONTINUES
80 GOTO 30
500 A(N) = AIN(3)
510 N=N+1
520 IF N = 100 THEN ONTICK 0,500
530 RETI
MEASURING HIGHER VOLTAGES
Voltages higher than + 5V are measur ed by inserting a
series resistor to the input.
The table below shows resistor values for some input
voltages using the 0-5V range.
Maximum
Input Voltage Resistor
6 20K
12.5 150K
24 380K
Use the following formula to determine the series
resistance necessary for a m aximum voltage input:
Rs = Vi * 20000 - 100000 0 - 5V range
Rs = Vi * 40000 - 100000 0 - 2.5V range
Rs is the resistor value in ohms in ser ies with the input.
Vi is the maximum input voltage. When Rs is negative
or zero, a series resistor is not necessary.
A high Rs value can cause noisy readings. This is
because the resistor acts as an antenna. To reduce noise,
place a 0.1 mfd to 1 mfd capacitor between the input
terminal and ground.
NOTE: When an input voltage exceeds the input range,
other channel values are affected.
