AVL F-FEM-CON User Manual

Operation
62
F-FEM-CON — User’s Guide
4.6.10 Sensor types and attributes
Not all combinations of sensor attributes and sensor types can be used on all
channels. For the valid combinations, please refer to the F-FEM Parameteriza-
tion manual, table Interrelationship between sensor attribute and valid sensor
type.
Cut-off frequencies of the input circuits for the various sensor types:
*) for sensor attribute "Freq Z-Unsigned" up to 500 kHz
4.6.11 Accuracy Specification
The measuring time influences the accuracy of the speed acquisition in the
following ways:
With a measuring time of 1 ms and a quartz frequency of 20 MHz (accuracy
25 ppm), the quantization error is 50 ns. This corresponds to a quantization error
of 50ns/1ms = 50 ppm or an accuracy of 14.29 bit. In this case, the counter
counts up to 20000, which requires a 15-bit width (log
2
[20000] = 14.29 bit).
With a measuring time of 2 ms, the quantization error is also 50 ns. However,
this corresponds to a quantization error of 50ns/2ms = 25 ppm or an accuracy of
15.29 bit, etc.
Sensor Type Cut-off Frequency
Min Max Unit
Incremental Encoder
Nullspur
0
0
500
1 *)
kHz
kHz
Digital Input 0 500 kHz
Inductive 0 400
(at 20 V
ss
)
kHz
Hall 0.001 300 kHz
Tab. 11
Information
From PUMA Open version 1.5 onward, it is checked, whether the input values
are within the specified range. You find the valid ranges in the F-FEM Parameter-
ization manual.
Make sure that the adjustment- and calibration points are within the valid range!
Quantity Value Comment
Basic accuracy of reference clock +
25 ppm at temperatures from 0 to 60 °C
Resolution (reference clock) 50 ns
20 ns *)
at 20 MHz
50 MHz *)
Counter width 16 bit hardware extended to 32 bit by software
Result width 32 bit floating point according to IEEE notation
Tab. 12
*) valid for F-FEM-CON Advanced

AVL F-FEM-CON Specifications

General

Brand	AVL
Model	F-FEM-CON
Category	Measuring Instruments
Language	English