Horner APG XLe OCS HE-XE103-10 User Manual
Page 3
MAN0848-02
21 August 2007
PAGE 3
Specifications / Installation
XLE103-10
5
Analog Conditioning
5.1
Filter
Filter Constant sets the level of digital filtering according to the following
chart.
Digital Filtering.
The illustration above demonstrates the effect of digital
filtering (set with Filter Constant) on module response to a
temperature change.
It is recommended that the filter constant for the HE-XE103-10 be set to a
value of 7. This will minimize noise and jitter, improve effective resolution,
and provide adequate speed for most temperature monitor and control
applications.
5.2
Thermistor Linearization
Thermistors are measured using a half-bridge circuit that exhibits variable resolution
and the associated increased measurement range.
Temperature, degrees C
Resolution, degrees C
-55
1.05
-35
0.36
-15
0.17
5
0.11
25
0.1
45
0.13
65
0.22
85
0.30
105
0.55
125
0.85
145
1.35
Best resolution is at 25°C, 77°F. With a constant 0.1°C resolution circuit, the
measurement range would only extend from –26°C to + 76°C.
Linearization must be performed by the user in the ladder application code, using 26
internal %R registers per channel. The example below uses %R1-26 to linearize one
channel - %AI1. Linearization consists of the following example steps.
1. Load the desired linearization coefficients into a table on First Scan using a Move
Constant Data block.
Registers (Real)
Degrees C
Degrees F
R0011
-1.94454e-028
-3.50017e-028
R0013
2.40268e-023
4.32483e-023
R0015
-1.24101e-018
-2.23381e-018
R0017
3.46655e-014
6.23979e-014
R0019
-5.69403e-010
-1.02493e-009
R0021
5.62368e-006
1.01226e-005
R0023
-0.0353121
-0.0635617
R0025
163.878
326.981
2. Load %AI0001 into %R0001 as a Real.
3. Perform the Real Math Expression
%R3 = (((%R11*%R1+%R13)*%R1+%R15)*%R1+%R17)
4. Perform the Real Math Expression %R5 =
(((%R3*%R1+%R19)*%R1+%R21)*%R1+%R23)*%R1+%R25
5. Load %R0005 result into another register such as %R0007 to save the temperature
value.
Steps 2 though 5 can be on a single rung.
The expression rung may be copied, substituting %AI0002 and %R00011 for %AI0001 and
%R0007, and used to linearize the second channel. Contact Horner APG for an example file
containing the above program.
5.3
Thermistor types
The HE-XE103-10 with the given example ladder code supports Kele Engineering Precon
Type III, 10 K
Ω
thermistors. It also directly supports the following 10 K
Ω
(Beta=3574)
thermistors from Yellow Springs Instruments (YSI).
44006 46006
44106 46031
44406 46041
44031 44907
45006 44908
6
I/O Register Map
Registers
Description
%I1 to %I24
Digital Inputs
%I32
Output Fault
%I25 to %I31
Reserved
%Q1 to %Q16
Digital outputs
%Q17
Clear HSC1 accumulator to 0
%Q18
Totalizer: Clear HSC2
Quadrature 1-2: Accumulator 1
Reset to max – 1
%Q19
Clear HSC3 Accumulator to 0
%Q20
Totalizer: Clear HSC4
Quadrature 3-4: Accumulator 3
Reset to max – 1
%Q21 to %Q32
Reserved
%AI1 to %AI4
Analog inputs
%AI5, %AI6
HSC1 Accumulator
%AI7, %AI8
HSC2 Accumulator
%AI9, %AI10
HSC3 Accumulator
%AI11, %AI12
HSC4 Accumulator
%AQ1, %AQ2
PWM1 Duty Cycle
%AQ3, %AQ4
PWM2 Duty Cycle
%AQ5, %AQ6
PWM Prescale
%AQ7, %AQ8
PWM Period
%AQ9 to %AQ14
Analog outputs
Note: Not all XLe units contain the I/O listed in this table.
Registers
PWM
HSC
Stepper
%AQ1
Start
Frequency
%AQ2
PWM1 Duty
Cycle
(32 bit)
HSC1
Preset
Value
Run
Frequency
%AQ3
%AQ4
PWM2 Duty
Cycle
(32 bit)
HSC2
Preset
Value
Accel Count
(32 bit)
%AQ5
%AQ6
PWM Prescale
(32 bit)
Run Count
(32 bit)
%AQ7
%AQ8
PWM Period
(32 bit)
Decel Count
(32 bit)
%Q1
Run
%I30
Ready/Done
%I31
Error
60
20
100
40
80
20
0
10
100
90
80
70
60
50
40
30
Scans
0
1
2
3
4
5
6
0
7
%
C
o
m
p
le
te
[
]
Filter
Constant