Command 4 conversion equation setup (analog) – Vernier LabPro User Manual
Page 39
Revision Date: 08/02/02
LabPro Technical Manual
39
Command 4
Conversion Equation Setup (Analog)
This command sets up parameters to convert physical units measured by LabPro into a more useful
measurement unit such as newtons or
°
C.
Syntax: {4, channel[, equtype[, K
0
, K
1
]]}
Parameter List:
channel
– indicates channel on which this command operates. The possible values are
Channel
Description
0
All channels
1 – 4
Analog channels 1 through 4
11, 12
Sonic Channel 1, Sonic Channel 2
equtype
– indicates what conversion equation is to be applied to the desired channel. Equation types
1 and 2 use a modified syntax. All equtype values except 13 apply only to analog channels 1
through 4. The possible values are:
equtype
Equation Type
Equation
Restrictions
-1
Unary. Hex value
representing
5V/16bits.
Data is returned in
hexadecimal format.
May only be used
with channel value
of 0.
1
Polynomial
K
0
+ K
1
X + K
2
X
2
+ ... + K
n
X
n
1
≤
N
≤
9
2
Mixed Polynomial
K
-m
X
-m
+ ... + K
-1
X
-1
+ K
0
+
K
1
X + ... + K
n
X
n
0
≤
N
≤
4
0
≤
M
≤
4
M + N >0
X
≠
0
3
Power
K
0
X
(K1)
X>0
4
Modified power
K
0
K
1
(X)
K
1
>0
5
Logarithmic
K
0
+ K
1
ln(X)
X>0
6
Modified logarithmic
K
0
+ K
1
ln(1/X)
X>0
7
Exponential
K
0
e
(K1X)
No restrictions other
than overflow.
8
Modified exponential
K
0
e
(K1/X)
X
≠
0
9
Geometric
K
0
X
(K1X)
X
≥
0
10
Modified geometric
K
0
X
(K1/X)
X>0
11
Reciprocal logarithmic
[K
0
+ K
1
ln(K
2
X)]
-1
K
2
X>0
12
Steinhart-Hart Model
[K
0
+ K
1
(ln 1000X) + K
2
(ln
1000X)
3
…]
1
X>0
13
K
0
in units of K
1
Only applies to
channels 11 and 12.
K0 & K1
– Except when equtype =13, these are the coefficients for the equation defined by equtype
and are type float. When equtype=13, K0 is the ambient temperature in units defined by K1,
and K1 may have the following values:
K1
Temperature Units
0
°
Celsius
1
°
Fahrenheit
2
°
Celsius
3
Kelvin
4
Rankin